MINOR: startup: add bind_listeners

MINOR: startup: add bind_listeners

Let's encapsulate here the code, which tries to bind listeners for the new
process in a separate function. This will make the main() code more readable.
Master process, even if it has failed while reading its new configuration, has
to bind its master CLI sockets. So like this we will can call this function in
the master recovery mode.

Master CLI socket address and port for external connections (user, monitoring
tools) are provided for now only via the command line. So, master, even after
this failure can and must reestablish master CLI connections again.