Prevent recaptcha webview from keeping youtube loaded in background

After the cookies are extracted from the recaptcha webview make it load an empty
page to prevent youtube being loaded unecessarily in the background.

app/src/main/java/org/schabi/newpipe/error/ReCaptchaActivity.java

@@ -162,6 +162,9 @@ public class ReCaptchaActivity extends AppCompatActivity {
             setResult(RESULT_OK);
         }
 
+        // Navigate to blank page (unloads youtube to prevent background playback)
+        recaptchaBinding.reCaptchaWebView.loadData("", "text/html", null);
+
         final Intent intent = new Intent(this, org.schabi.newpipe.MainActivity.class);
         intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
         NavUtils.navigateUpTo(this, intent);