Merge pull request #23519 from kamipo/mariadb_does_not_support_json_type

MariaDB does not support JSON type

activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

@@ -42,7 +42,7 @@ def initialize(connection, logger, connection_options, config)
       end
 
       def supports_json?
-        version >= '5.7.8'
+        !mariadb? && version >= '5.7.8'
       end
 
       # HELPER METHODS ===========================================