Add a e2e test for the previous 2 commits

ref #3231

tests/end_to_end/__main__.py

@@ -551,6 +551,22 @@ if __name__ == '__main__':
                      partial(expect_stanza, "/message[@from='{irc_server_one}']/body[text()='ERROR: Closing Link: localhost (Client Quit)']"),
                      partial(expect_stanza, "/message[@from='{irc_server_one}']/body[text()='ERROR: Connection closed.']"),
                  ]),
+        Scenario("not_connected_error",
+                 [
+                     handshake_sequence(),
+                     partial(send_stanza,
+                             "<presence type='unavailable' from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' />"),
+                     partial(send_stanza,
+                             "<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' />"),
+                     connection_sequence("irc.localhost", '{jid_one}/{resource_one}'),
+                     partial(expect_stanza,
+                             "/message/body[text()='Mode #foo [+nt] by {irc_host_one}']"),
+                     partial(expect_stanza,
+                             ("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@role='moderator']",
+                              "/presence/muc_user:x/muc_user:status[@code='110']")
+                             ),
+                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}'][@type='groupchat']/subject[not(text())]"),
+                 ]),
         Scenario("irc_server_disconnection",
                  [
                      handshake_sequence(),