Workaround 452d6aa9 breaking TrustworthySafe03

This is only a temporary kludge until the issue workarounded by 452d6aa9
gets properly fixed

testsuite/tests/safeHaskell/safeInfered/TrustworthySafe03.hs

 {-# LANGUAGE Trustworthy #-}
 {-# OPTIONS_GHC -Wall #-}
+{-# OPTIONS_GHC -fwarn-trustworthy-safe #-} -- temp broken by 452d6aa95
 
 -- | This module is marked trustworthy but should be inferable as -XSafe.
 -- Warning enabled through `-W`.