System: userdel returns 6 when no maildir is deleted but homedir is

So we agree on that one!

private/lib/System.py

@@ -181,7 +181,7 @@ class System:
             return True
         else:
             ret = subprocess.call(cc)
-            if ret != 0 or ret != 6:
+            if ret != 0 and ret != 6:
                 raise lib.UserExceptions.UnknownReturnCode(
                     f"Could not delete user with command {cc}. Return code: {ret}")
             return True