Correct shlibs of freeswitch-all wrt libfreeswitch1

The freeswitch-all package provides libfreeswitch1, so any
shlibs-generated dependency should be for libfreeswitch1 rather than
freeswitch-all.

Because dh_shlibdeps / dpkg-shlibdeps searches for shlibs files in
debian/*/DEBIAN/ it was sometimes using freeswitch-all rather than
libfreeswitch1 to satisfy dependencies for freeswitch.so.1.

FS-6029 --resolve