Avoid emoji mismatch and allow to only enable chosen emojis (#35692) (#35705)

Backport #35692 by wxiaoguang

Fix #23635

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

custom/conf/app.example.ini

@@ -1343,6 +1343,10 @@ LEVEL = Info
 ;; Dont mistake it for Reactions.
 ;CUSTOM_EMOJIS = gitea, codeberg, gitlab, git, github, gogs
 ;;
+;; Comma separated list of enabled emojis, for example: smile, thumbsup, thumbsdown
+;; Leave it empty to enable all emojis.
+;ENABLED_EMOJIS =
+;;
 ;; Whether the full name of the users should be shown where possible. If the full name isn't set, the username will be used.
 ;DEFAULT_SHOW_FULL_NAME = false
 ;;