test: correctly skip invalid tests

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

test/web/email/group_test.exs

@@ -14,7 +14,7 @@ defmodule Mobilizon.Web.Email.GroupTest do
   import Mobilizon.Factory
 
   describe "Notify of new event" do
-    @tag @skip
+    @tag :skip
     test "members, followers, execept the ones that disabled it" do
       {_user_creator, actor} = insert_user_with_settings("user@creator.com")
       %Actor{} = group = insert(:group)