feat: do not create device messages for IMAP authentication errors

Authentication failures may happen because of internal server errors.
Device message saying "Please check if the email address and the password are correct"
was written for classic email setups when the user knows the password.
For users of chatmail relays this message is not actionable,
but still appears when relay fails to check the password.

python/tests/test_1_online.py

@@ -1133,8 +1133,9 @@ def test_configure_error_msgs_wrong_pw(acfactory):
         print(f"Configuration progress: {ev.data1}")
         if ev.data1 == 0:
             break
-    # Password is wrong so it definitely has to say something about "password"
-    assert "password" in ev.data2
+    # Password is wrong so the error should be about authentication
+    # and not e.g. connection failure.
+    assert "Authentication" in ev.data2
 
     ac1.stop_io()
     ac1.set_config("mail_pw", "abc")  # Wrong mail pw
@@ -1144,10 +1145,7 @@ def test_configure_error_msgs_wrong_pw(acfactory):
         print(f"Configuration progress: {ev.data1}")
         if ev.data1 == 0:
             break
-    assert "password" in ev.data2
-    # Account will continue to work with the old password, so if it becomes wrong, a notification
-    # must be shown.
-    assert ac1.get_config("notify_about_wrong_pw") == "1"
+    assert "Authentication" in ev.data2
 
 
 def test_configure_error_msgs_invalid_server(acfactory):