Remove the developer warning on the rest api (#10441)

packages/rocketchat-api/server/api.js

@@ -146,20 +146,7 @@ class API extends Restivus {
 							return RocketChat.API.v1.failure(e.message, e.error);
 						}
 
-						result = result ? result : RocketChat.API.v1.success();
-
-						if (
-							/(channels|groups)\./.test(route)
-							&& result
-							&& result.body
-							&& result.body.success === true
-							&& (result.body.channel || result.body.channels || result.body.group || result.body.groups)
-						) {
-							// TODO: Remove this after three versions have been released. That means at 0.64 this should be gone. ;)
-							result.body.developerWarning = '[WARNING]: The "usernames" field has been removed for performance reasons. Please use the "*.members" endpoint to get a list of members/users in a room.';
-						}
-
-						return result;
+						return result ? result : RocketChat.API.v1.success();
 					};
 
 					for (const [name, helperMethod] of this.getHelperMethods()) {