Fix tests. Input is a Polygon, and output is a multipolygon

tests/src/python/test_qgsgeometry_avoid_intersections.py

@@ -60,7 +60,7 @@ def testNoSliverPolygons(self):
         # create a geometry and remove its intersections with other geometries
 
         g = QgsGeometry.fromWkt(newg_wkt)
-        assert g.avoidIntersections([l]) == 0
+        assert g.avoidIntersections([l]) == 2
 
         # the resulting multi-polygon must have exactly three parts
         # (in QGIS 2.0 it has one more tiny part that appears at the border between two of the original polygons)