Get rid of get_parent_until.

jedi/api/helpers.py

@@ -299,7 +299,7 @@ def cache_call_signatures(evaluator, context, bracket_leaf, code_lines, user_pos
     whole = '\n'.join(other_lines + [before_cursor])
     before_bracket = re.match(r'.*\(', whole, re.DOTALL)
 
-    module_path = bracket_leaf.get_parent_until().path
+    module_path = bracket_leaf.get_root_node().path
     if module_path is None:
         yield None  # Don't cache!
     else: