fix Invidious channels being accepted by YoutubeStreamLinkHandlerFactory (#527)

fixes #524, see it for more details

Author: B0pol

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/linkHandler/YoutubeStreamLinkHandlerFactory.java

@@ -36,7 +36,7 @@
 
 public class YoutubeStreamLinkHandlerFactory extends LinkHandlerFactory {
 
-    private static final Pattern YOUTUBE_VIDEO_ID_REGEX_PATTERN = Pattern.compile("([a-zA-Z0-9_-]{11})");
+    private static final Pattern YOUTUBE_VIDEO_ID_REGEX_PATTERN = Pattern.compile("^([a-zA-Z0-9_-]{11})");
     private static final YoutubeStreamLinkHandlerFactory instance = new YoutubeStreamLinkHandlerFactory();
 
     private YoutubeStreamLinkHandlerFactory() {

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeStreamLinkHandlerFactoryTest.java

@@ -42,6 +42,8 @@ public void getIdForInvalidUrls() {
         invalidUrls.add("https://www.youtube.com/watch?v=jZViOEv90d");
         invalidUrls.add("https://www.youtube.com/watchjZViOEv90d");
         invalidUrls.add("https://www.youtube.com/");
+        invalidUrls.add("https://www.youtube.com/channel/UCBR8-60-B28hp2BmDPdntcQ");
+        invalidUrls.add("https://invidio.us/channel/UCBR8-60-B28hp2BmDPdntcQ");
         for (String invalidUrl : invalidUrls) {
             Throwable exception = null;
             try {