Merge pull request #12614 from rabbitmq/mergify/bp/v4.0.x/pr-12613

rabbit_prometheus_http_SUITE: Start broker once in `special_chars` group (backport #12613)

Author: dumbbell

deps/rabbitmq_prometheus/test/rabbit_prometheus_http_SUITE.erl

@@ -246,7 +246,7 @@ init_per_group(special_chars, Config0) ->
                {connection, VHostConn},
                {channel, VHostCh}
                |Config1],
-    init_per_group(special_chars, Config2, []);
+    Config2;
 
 init_per_group(authentication, Config) ->
     Config1 = rabbit_ct_helpers:merge_app_env(