use proper dc function for contact listing as per review from @r10s

python/src/deltachat/account.py

@@ -324,6 +324,7 @@ class EventLogger:
         return ev
 
     def get_matching(self, event_name_regex):
+        print ("-- waiting for event with regex:", event_name_regex, "--")
         rex = re.compile("(?:{}).*".format(event_name_regex))
         while 1:
             ev = self.get()

python/src/deltachat/chatting.py

@@ -150,7 +150,7 @@ class Chat(object):
         :returns: None
         """
         dc_array = ffi.gc(
-            lib.dc_get_contacts(self._dc_context, lib.DC_GCL_ADD_SELF, ffi.NULL),
+            lib.dc_get_chat_contacts(self._dc_context, self.id),
             lib.dc_array_unref
         )
         return list(iter_array(