Remove proguard rules for optional jsoup classes

The underlying problem is fixed with jsoup 1.12.2. See https://github.com/TeamNewPipe/NewPipeExtractor/pull/1480.

Revert 6c5d58bed3 /  #13038.

app/proguard-rules.pro

@@ -16,11 +16,6 @@
 -dontwarn javax.script.**
 -keep class jdk.dynalink.** { *; }
 -dontwarn jdk.dynalink.**
-# Rules for jsoup
-# Ignore intended-to-be-optional re2j classes - only needed if using re2j for jsoup regex
-# jsoup safely falls back to JDK regex if re2j not on classpath, but has concrete re2j refs
-# See https://github.com/jhy/jsoup/issues/2459 - may be resolved in future, then this may be removed
--dontwarn com.google.re2j.**
 
 ## Rules for ExoPlayer
 -keep class com.google.android.exoplayer2.** { *; }