fix PeerTube description and add more description tests

actually, the max description length is 250 after request with our extractor.
during my tests, I made API requests with Firefox, copy/pasted into echo "insert description" | wc, and it was giving a wrong length, maybe due to the escapers, I have no idea
anyway, it's now fixed

Author: B0pol

extractor/src/main/java/org/schabi/newpipe/extractor/services/peertube/extractors/PeertubeStreamExtractor.java

@@ -76,7 +76,8 @@ public String getDescription() throws ParsingException {
         } catch (ParsingException e) {
             return "No description";
         }
-        if (desc.length() >= 255 && desc.substring(desc.length() - 3).equals("...")) {
+        if (desc.length() == 250 && desc.substring(desc.length() - 3).equals("...")) {
+            //if description is shortened, get full description
             Downloader dl = NewPipe.getDownloader();
             try {
                 Response response = dl.get(getUrl() + "/description");

extractor/src/test/java/org/schabi/newpipe/extractor/services/peertube/PeertubeStreamExtractorDefaultTest.java

@@ -29,7 +29,8 @@
  */
 public class PeertubeStreamExtractorDefaultTest {
     private static PeertubeStreamExtractor extractor;
-    private static final String expectedDescription = "**[Want to help to translate this video?](https://weblate.framasoft.org/projects/what-is-peertube-video/)**\r\n\r\n**Take back the control of your videos! [#JoinPeertube](https://joinpeertube.org)**\r\n*A decentralized video hosting network, based on free/libre software!*\r\n\r\n**Animation Produced by:** [LILA](https://libreart.info) - [ZeMarmot Team](https://film.zemarmot.net)\r\n*Directed by* Aryeom\r\n*Assistant* Jehan\r\n**Licence**: [CC-By-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)\r\n\r\n**Sponsored by** [Framasoft](https://framasoft.org)\r\n\r\n**Music**: [Red Step Forward](http://play.dogmazic.net/song.php?song_id=52491) - CC-By Ken Bushima\r\n\r\n**Movie Clip**: [Caminades 3: Llamigos](http://www.caminandes.com/) CC-By Blender Institute\r\n\r\n**Video sources**: https://gitlab.gnome.org/Jehan/what-is-peertube/";
+    private static final String expectedLargeDescription = "**[Want to help to translate this video?](https://weblate.framasoft.org/projects/what-is-peertube-video/)**\r\n\r\n**Take back the control of your videos! [#JoinPeertube](https://joinpeertube.org)**\r\n*A decentralized video hosting network, based on free/libre software!*\r\n\r\n**Animation Produced by:** [LILA](https://libreart.info) - [ZeMarmot Team](https://film.zemarmot.net)\r\n*Directed by* Aryeom\r\n*Assistant* Jehan\r\n**Licence**: [CC-By-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)\r\n\r\n**Sponsored by** [Framasoft](https://framasoft.org)\r\n\r\n**Music**: [Red Step Forward](http://play.dogmazic.net/song.php?song_id=52491) - CC-By Ken Bushima\r\n\r\n**Movie Clip**: [Caminades 3: Llamigos](http://www.caminandes.com/) CC-By Blender Institute\r\n\r\n**Video sources**: https://gitlab.gnome.org/Jehan/what-is-peertube/";
+    private static final String expectedSmallDescription = "https://www.kickstarter.com/projects/1587081065/nothing-to-hide-the-documentary";
 
     @BeforeClass
     public static void setUp() throws Exception {
@@ -52,8 +53,23 @@ public void testGetTitle() throws ParsingException {
     }
 
     @Test
-    public void testGetDescription() throws ParsingException {
-        assertEquals(expectedDescription, extractor.getDescription());
+    public void testGetLargeDescription() throws ParsingException {
+        assertEquals(expectedLargeDescription, extractor.getDescription());
+    }
+
+    @Test
+    public void testGetEmptyDescription() throws Exception {
+        PeertubeStreamExtractor extractorEmpty = (PeertubeStreamExtractor) PeerTube.getStreamExtractor("https://framatube.org/api/v1/videos/d5907aad-2252-4207-89ec-a4b687b9337d");
+        extractorEmpty.fetchPage();
+        assertEquals("No description", extractorEmpty.getDescription());
+    }
+
+    @Test
+    public void testGetSmallDescription() throws Exception {
+        PeerTube.setInstance(new PeertubeInstance("https://peertube.cpy.re", "PeerTube test server"));
+        PeertubeStreamExtractor extractorSmall = (PeertubeStreamExtractor) PeerTube.getStreamExtractor("https://peertube.cpy.re/videos/watch/d2a5ec78-5f85-4090-8ec5-dc1102e022ea");
+        extractorSmall.fetchPage();
+        assertEquals(expectedSmallDescription, extractorSmall.getDescription());
     }
 
     @Test