Fix a Qt error in loadUI that returned an error related to connectSlo…

…tsByName. The error happens following the change in python/cpython#13589. Basically it looks like connectSlotsByName causes all properties of the Qt class to be accessed, but the viewer property didn't previously work before the load_ui call since _viewer wasn't defined and an AttributeError was raised. The fix here is to make sure that self._viewer is defined before load_ui is called.

glue/viewers/profile/qt/profile_tools.py

@@ -72,12 +72,13 @@ def __init__(self, parent=None):
 
         super(ProfileTools, self).__init__(parent=parent)
 
+        self._viewer = weakref.ref(parent)
+
         self.ui = load_ui('profile_tools.ui', self,
                           directory=os.path.dirname(__file__))
 
         fix_tab_widget_fontsize(self.ui.tabs)
 
-        self._viewer = weakref.ref(parent)
         self.image_viewer = None
 
     @property