[processing] fix duplicates fields name in field calculator algorithm when switching between layers (followup 2185d42)

slarosa · slarosa · commit 6c126a3a960d · 2017-05-23T00:17:23.000+02:00
cherry-picked from 48ecee5
diff --git a/python/plugins/processing/algs/qgis/ui/FieldsCalculatorDialog.py b/python/plugins/processing/algs/qgis/ui/FieldsCalculatorDialog.py
@@ -102,9 +102,8 @@ def initContext(self):
 
     def updateLayer(self):
         self.layer = dataobjects.getObject(self.cmbInputLayer.currentText())
-        self.initContext()
         self.builder.setLayer(self.layer)
-        self.builder.loadFieldNames()
+        self.initContext()
         self.populateFields()
 
     def setupSpinboxes(self, index):
