OWProjectionWidgetBase: Update when domain is changed

Author: janezd

Orange/widgets/visualize/utils/widget.py

@@ -440,6 +440,8 @@ def set_data(self, data):
         self.openContext(self.data)
         self._invalidated = not (
             data_existed and self.data is not None and
+            effective_data.domain.checksum()
+            == self.effective_data.domain.checksum() and
             array_equal(effective_data.X, self.effective_data.X))
         if self._invalidated:
             self.clear()