Increase the maximum viewer scale to 2500 percent

After PR 19128 huge zoom levels should no longer be an issue, so let's increase the maximum viewer scale a bit.

Author: Snuffleupagus

web/ui_utils.js

@@ -19,7 +19,7 @@ const DEFAULT_SCALE_VALUE = "auto";
 const DEFAULT_SCALE = 1.0;
 const DEFAULT_SCALE_DELTA = 1.1;
 const MIN_SCALE = 0.1;
-const MAX_SCALE = 10.0;
+const MAX_SCALE = 25.0;
 const UNKNOWN_SCALE = 0;
 const MAX_AUTO_SCALE = 1.25;
 const SCROLLBAR_PADDING = 40;