debian: tweak .install: less wildcards

With the upcoming addition of libosmo-mgcp, when we try the same scheme
of wildcards there, it would also include all of the other libraries:

  *mgcp*.so.*

There we will have to clarify that we mean exactly:

  libosmo-mgcp.so.*

This is a cosmetic change to also be less ambiguous for the current libs:
I prefer to state exactly which parts of the file names may vary, so that
we have a firmer understanding of what is being installed.

Change-Id: I6a3f3b9efa08eb9c5cdca3e02f8fab4a96c28ad5
3 files changed