Squish: Add exception logging

Might help to figure out a problem on the build machines.

Change-Id: I1483a508d490e3cd4312d91c62d3e4a2891d0b10
Reviewed-by: Robert Loehning <robert.loehning@qt.io>

tests/system/shared/editor_utils.py

@@ -85,6 +85,8 @@ def menuVisibleAtEditor(editor, menuInList):
             menuInList[0] = menu
         return success
     except:
+        t, v = sys.exc_info()[:2]
+        test.log("Exception: %s" % str(t), str(v))
         return False
 
 # this function checks whether the given global point (QPoint)