url signature fix

* fixed stacktrace
* changed player url
* took regex fix from youtube-dl

final fix taken from youtube-dl

app/src/main/java/org/schabi/newpipe/detail/StreamInfoWorker.java

@@ -125,10 +125,13 @@ public class StreamInfoWorker {
                 e.printStackTrace();
             } catch (YoutubeStreamExtractor.DecryptException de) {
                 // custom service related exceptions
+                ErrorActivity.reportError(h, a, de, VideoItemDetailFragment.class, null,
+                        ErrorActivity.ErrorInfo.make(ErrorActivity.REQUESTED_STREAM,
+                                service.getServiceInfo().name, videoUrl, R.string.youtube_signature_decryption_error));
                 h.post(new Runnable() {
                     @Override
                     public void run() {
-                        onStreamInfoReceivedListener.onError(R.string.youtube_signature_decryption_error);
+                        a.finish();
                     }
                 });
                 de.printStackTrace();

app/src/main/java/org/schabi/newpipe/extractor/Parser.java

@@ -42,17 +42,25 @@ public class Parser {
     }
 
     public static String matchGroup1(String pattern, String input) throws RegexException {
+        return matchGroup(pattern, input, 1);
+    }
+
+    public static String matchGroup(String pattern, String input, int group) throws RegexException {
         Pattern pat = Pattern.compile(pattern);
         Matcher mat = pat.matcher(input);
         boolean foundMatch = mat.find();
         if (foundMatch) {
-            return mat.group(1);
+            return mat.group(group);
         }
         else {
             //Log.e(TAG, "failed to find pattern \""+pattern+"\" inside of \""+input+"\"");
+            if(input.length() > 1024) {
+                throw new RegexException("failed to find pattern \""+pattern);
+            } else {
                 throw new RegexException("failed to find pattern \"" + pattern + " inside of " + input + "\"");
             }
         }
+    }
 
     public static Map<String, String> compatParseMap(final String input) throws UnsupportedEncodingException {
         Map<String, String> map = new HashMap<>();

app/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeStreamExtractor.java

@@ -791,10 +791,15 @@ public class YoutubeStreamExtractor extends StreamExtractor {
 
         try {
             Downloader downloader = NewPipe.getDownloader();
+            if(!playerUrl.contains("https://youtube.com")) {
+                //sometimes the https://youtube.com part does not get send with
+                //than we have to add it by hand
+                playerUrl = "https://youtube.com" + playerUrl;
+            }
             String playerCode = downloader.download(playerUrl);
 
             decryptionFuncName =
-                    Parser.matchGroup1("\\.sig\\|\\|([a-zA-Z0-9$]+)\\(", playerCode);
+                    Parser.matchGroup("([\"\\'])signature\\1\\s*,\\s*([a-zA-Z0-9$]+)\\(", playerCode, 2);
 
             String functionPattern = "("
                     + decryptionFuncName.replace("$", "\\$")