contrib: integrate RPM spec

Remove OpenSUSE bug report link, set version to 0.0.0, make it build with CentOS 8 etc.

Related: OS#4550
Change-Id: I3e135e5e7807688366598a24e121550d6292906c
diff --git a/contrib/libosmo-abis.spec b/contrib/libosmo-abis.spec
index ac91c60..86b0c1b 100644
--- a/contrib/libosmo-abis.spec
+++ b/contrib/libosmo-abis.spec
@@ -12,14 +12,8 @@
 # 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/
-#
-
-
-%define version_unconverted 0.8.0.26
-
 Name:           libosmo-abis
-Version:        0.8.0.26
+Version:        0.0.0
 Release:        0
 Summary:        Osmocom library for A-bis interface between BTS and BSC
 License:        AGPL-3.0-or-later AND GPL-2.0-or-later
@@ -27,7 +21,6 @@
 Url:            https://osmocom.org/projects/libosmo-abis/wiki/Libosmo-abis
 
 Source:         %name-%version.tar.xz
-Patch1:         osmo-talloc.diff
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 BuildRequires:  automake >= 1.6
 #BuildRequires:  dahdi-linux-devel
@@ -103,7 +96,6 @@
 
 %prep
 %setup -q
-%patch -P 1 -p1 -F2
 
 %build
 echo "%version" >.tarball-version