Updated RELEASE_NOTES.

RELEASE_NOTES.md

@@ -10,7 +10,7 @@ Fixed semaphore name conflicts (contributed by Poesty).
 
 Fix warning in ugly pointer substraction (contributed by Saagar Jha).
 
-Mastodon API: implemented notification type filters.
+Mastodon API: implemented notification type filters, fixed (partially) the issue with mentions with server.
 
 ## 2.30