MCS: fallback to port 443 if 5228 is blocked

According to Google Firebase's doc, other ports than 5228 can be used:

    If your organization has a firewall to restrict traffic to or from
    the Internet, you need to configure it to allow mobile devices to
    connect with FCM in order for devices on your network to receive
    messages. FCM typically uses port 5228, but it sometimes uses 443,
    5229, and 5230.

Src: https://firebase.google.com/docs/cloud-messaging/concept-options#messaging-ports-and-your-firewall

As suggested by @mar-v-in, it is enough to first try 5228 and then only
try with 443 as fall back port. Indeed, it would be surprising to find
any firewall blocking port 5228 but not 5229.

If none of these ports, a new attempt will be done later as before.

Closes: https://github.com/microg/GmsCore/issues/408


Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>