fix: mention container long click

Co-authored-by: NekoInverter <chsqwyx@gmail.com>

TMessagesProj/src/main/java/org/telegram/ui/ChatActivity.java

@@ -7282,6 +7282,7 @@ public class ChatActivity extends BaseFragment implements NotificationCenter.Not
             if (getParentActivity() == null || !mentionContainer.getAdapter().isLongClickEnabled()) {
                 return false;
             }
+            position--;
             Object object = mentionContainer.getAdapter().getItem(position);
             int start = mentionContainer.getAdapter().getResultStartPosition();
             int len = mentionContainer.getAdapter().getResultLength();