TT#88050 Remove dependencies on obsolete packages

These packages got removed before the last LTS, so it is now safe to
remove dependencies on them.

Change-Id: Ia7d140f656b2bee56ff99be0c9108e15156d6894

debian/control

@@ -17,7 +17,5 @@ Depends:
  libnetaddr-ip-perl,
  ${misc:Depends},
  ${perl:Depends},
-Conflicts:
- ngcp-ossbss-billing (<= 3),
 Description: Rating daemon for the NGCP
  Perl daemon to rate CDRs in an NGCP.