Since commit b4999b60d4 we created PCU
sockets at hard-coded paths in the filesystem by default for all BTSs.
This is inflexible and prevents the use of multiple BSC instances on a
single filesystem, or the placement of the sockets in a more secure
location than /tmp.
The new approach with this patch is that
* no PCU sockets are created by default
* only for those BTSs where a 'pcu-socket' is configured via VTY,
the socket will actually be created
Change-Id: Ie9079470584777dcc31f85f9bf0808f479156ccb
Closes: OS#2293