[Processing] Compare lower file extension to "shp"

python/plugins/processing/tools/dataobjects.py

@@ -318,7 +318,7 @@ def exportVectorLayer(layer, supported=None):
             unicode(layer.source()).decode('ascii')
         except UnicodeEncodeError:
             isASCII = False
-        if not os.path.splitext()[1] in supported or not isASCII:
+        if not os.path.splitext()[1].lower() in supported or not isASCII:
             writer = QgsVectorFileWriter(
                 output, systemEncoding,
                 layer.pendingFields(), provider.geometryType(),