Dont save fingerprints to config and check certs with our own methods.
We should trust openssl to do all necessary checks.

Self signed certs can be added to cacert.pem and will not show up as
an error until the cert changes.

nbxmpp now saves all ssl errors and passes them, so now we loop over
all errors until all are confirmed or ignored by the user

Also cacerts are now saved in utf-8