Minor fixes that came over BM

- typo in quit confirmation dialog
- nicer traceback in unhandled exceptions

src/bitmessageqt/__init__.py

@@ -2618,7 +2618,7 @@ class MyForm(settingsmixin.SMainWindow):
                     QtGui.QMessageBox.Yes|QtGui.QMessageBox.No|QtGui.QMessageBox.Cancel, QtGui.QMessageBox.Cancel)
             if reply == QtGui.QMessageBox.No:
                 waitForPow = False
-            elif reply == QtGui.QMessage.Cancel:
+            elif reply == QtGui.QMessageBox.Cancel:
                 return
 
         if PendingDownloadQueue.totalSize() > 0:

src/debug.py

@@ -20,7 +20,6 @@ import logging
 import logging.config
 import os
 import sys
-import traceback
 import helper_startup
 import state
 helper_startup.loadConfig()
@@ -30,8 +29,7 @@ helper_startup.loadConfig()
 log_level = 'WARNING'
 
 def log_uncaught_exceptions(ex_cls, ex, tb):
-    logging.critical(''.join(traceback.format_tb(tb)))
-    logging.critical('{0}: {1}'.format(ex_cls, ex))
+    logging.critical('Unhandled exception', exc_info=(ex_cls, ex, tb))
 
 def configureLogging():
     have_logging = False