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: Idfe04c2e2609763387d1309f059c390b8e7ae938

.gitignore

@@ -64,3 +64,5 @@ doc/manuals/generated/
 doc/manuals/osmomsc-usermanual.xml
 doc/manuals/common
 doc/manuals/build
+
+contrib/osmo-pcu.spec

configure.ac

@@ -256,4 +256,5 @@ AC_OUTPUT(
     doc/manuals/Makefile
     contrib/Makefile
     contrib/systemd/Makefile
+    contrib/osmo-pcu.spec
     Makefile)

contrib/osmo-pcu.spec.in

@@ -12,24 +12,22 @@
 # license that conforms to the Open Source Definition (Version 1.9)
 # published by the Open Source Initiative.
 
-# Please submit bugfixes or comments via http://bugs.opensuse.org/
-#
-
-
 Name:           osmo-pcu
-Version:        0.8.0.126
+Version:        @VERSION@
 Release:        0
 Summary:        Osmocom GPRS Packet Control Unit (PCU)
 License:        GPL-2.0-only
 Group:          Productivity/Telephony/Servers
-URL:            https://osmocom.org/projects/osmopcu/wiki/OsmoPCU
+URL:            https://osmocom.org/projects/osmopcu
 Source:         %{name}-%{version}.tar.xz
 BuildRequires:  autoconf
 BuildRequires:  automake
 BuildRequires:  gcc-c++
 BuildRequires:  libtool
 BuildRequires:  pkgconfig >= 0.20
+%if 0%{?suse_version}
 BuildRequires:  systemd-rpm-macros
+%endif
 BuildRequires:  pkgconfig(libosmocore) >= 1.1.0
 BuildRequires:  pkgconfig(libosmogb) >= 1.1.0
 BuildRequires:  pkgconfig(libosmogsm) >= 1.1.0
@@ -55,6 +53,7 @@ make %{?_smp_mflags}
 %install
 %make_install
 
+%if 0%{?suse_version}
 %preun
 %service_del_preun %{name}.service
 
@@ -66,6 +65,7 @@ make %{?_smp_mflags}
 
 %post
 %service_add_post %{name}.service
+%endif
 
 %check
 make %{?_smp_mflags} check || (find . -name testsuite.log -exec cat {} +)