core (stdui): fixed cancellation of ContactList forms

src/tools/xml_tools.py

@@ -913,6 +913,8 @@ class ListWidget(InputWidget):
             - a tuple with a couple of string (value,label) if the label and the value differ
         @param selected (list[string]): list of the selected values
         @param styles (iterable[string]): flags to set the behaviour of the list
+            can be:
+                - multi: mutliple selection is allowed
         @param name (string)
         @param parent
         """