Update docker-compose.yml

update mysql command

examples/leantime/docker-compose.yml

@@ -12,7 +12,7 @@ services:
       MYSQL_DATABASE: 'leantime'
       MYSQL_USER: 'admin'
       MYSQL_PASSWORD: '321.qwerty'
-    command: --character-set-server=utf8 --collation-server=utf8_unicode_ci
+    command: --character-set-server=UTF8MB4 --collation-server=UTF8MB4_unicode_ci
     #networks:
     #  - proxy