Remove extra ] from feature flag code example

doc/development/feature_flags/controls.md

@@ -140,7 +140,7 @@ run the following in Slack:
 This sets a feature flag to `true` based on the following formula:
 
 ```ruby
-feature_flag_state = Zlib.crc32("some_feature<Actor>:#{actor.id}") % (100 * 1_000) < 25 * 1_000]
+feature_flag_state = Zlib.crc32("some_feature<Actor>:#{actor.id}") % (100 * 1_000) < 25 * 1_000
 # where <Actor>: is a `User`, `Group`, `Project` and actor is an instance
 ```