88474ba826
The previous fix https://github.com/mastodon/mastodon-android/pull/486 would break any connections to any instances using WEB_SAFE MIME64 encoding on the serverKey, which actually appears to be the usual case. This update reverts to the previous logic, but also converts standard MIME64 characters ('/' and '+') to their WEB_SAFE equivalents. This ensures the standard case of WEB_SAFE BASE64 serverKeys and the anomolous case of DEFAULT BASE64 keys both work.