Some "ctdb ..." commands can be run without having the main daemon running.

Some "ctdb ..." commands can be run without having the main daemon running.

In that case, when the main daemon is not running
the ctdb context will be initialized to NULL, since we can not connect.

Move the calls to read the ctdb socketname and connecting via libctdb to
only happen when we are executing a "ctdb ..." command that requires that we talk to the actual daemon.
Otherwise we will get an ugly SEGV for the "ctdb ..." commandline tool
when trying to run a command that is supposed to work also when the daemon is down.