contrib: integrate RPM spec

Remove OpenSUSE bug report link, set version to @VERSION@, make it build
with CentOS 8 etc.

Related: OS#4550
Change-Id: If5499e11d872e629a018fc77d5adf5d0cb863d48
diff --git a/.gitignore b/.gitignore
index bcd6847..ece4ee7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -72,3 +72,5 @@
 doc/manuals/osmomsc-usermanual.xml
 doc/manuals/common
 doc/manuals/build
+
+contrib/osmo-msc.spec