add missing import operator (#5724)

Gustry · nirvn · commit cf685f0f5f4b · 2017-11-24T22:03:19.000+07:00
diff --git a/python/plugins/processing/gui/ProcessingToolbox.py b/python/plugins/processing/gui/ProcessingToolbox.py
@@ -27,6 +27,7 @@
 
 __revision__ = '$Format:%H$'
 
+import operator
 import os
 
 from qgis.PyQt import uic
