qt5.qtwebkit.hyphen: fix tests

pkgs/development/libraries/qt-5/modules/qtwebkit.nix

···
       url = "http://dev-www.libreoffice.org/src/5ade6ae2a99bc1e9e57031ca88d36dad-${name}.tar.gz";
       sha256 = "304636d4eccd81a14b6914d07b84c79ebb815288c76fe027b9ebff6ff24d5705";
     };
+    postPatch = ''
+      patchShebangs tests
+    '';
     buildInputs = [ perl ];
   };
 in