Fix: libcib: Don't send CRM_OP_REGISTER from cib_remote client

The remote pacemaker-based server doesn't process it. This somehow clogs
up the message send/receive machinery. As a result, if the client makes
a synchronous call immediately after signon, the call will often time
out in pcmk__remote_ready() (while polling for readable data).

This issue was encountered when running cibadmin. In my testing, it
rarely occurred when running cibadmin under strace. So there was some
yet-undiagnosed timing issue caused by this gratuitous CRM_OP_REGISTER.

This fixes a regression introduced by d41c79a8, in which cibadmin often
times out when run by a remote CIB client. This regression has not made
it into any release.

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>