Squish: Restrict workaround to Qt4 builds

Change-Id: Ib67e6af786a557f50a6532bb0906ca9537ca22ad
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

tests/system/suite_general/tst_rename_file/test.py

@@ -50,7 +50,7 @@ def main():
                                ["Resources", "musicbrowser.qrc"],
                                ["QML", "musicbrowser.qml"]]:
         filenames = ["ABCD" + filename.upper(), "abcd" + filename.lower(), "test", "TEST", filename]
-        if platform.system() == 'Darwin':
+        if isQt4Build and platform.system() == 'Darwin':
             # avoid QTCREATORBUG-9197
             filtered = [filenames[0]]
             for i in range(1, len(filenames)):