Revert "msg/async: bump global_seq when retrying connection"

Revert "msg/async: bump global_seq when retrying connection"

This reverts commit ed65a7a53aedfd56343fdaefdeb59c22256f01b7.

See: https://github.com/ceph/ceph/pull/25956

Seems we don't want [39e8de2](https://github.com/ceph/ceph/commit/39e8de2d72e2541323f8ed9d8b68075fcbd02701)
to be backported.
It turns out the old async-connection implementation will
automatically bump the global_seq each time it switches to
the STATE_CONNECTING state and restarts the connecting process.

The same applies to mimic.

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>