[dist] Rpmlint: Silence unexpanded-macro warnings

Since we soon switch to the bundle gems service we need to solve
some rpmlint issues caused by the new gem files we store in the
vendor/ directory.

The rails gems have a couple of '%namespaced_name%' tags in their
filenames. There is nothing we can do about this. So we silence
this check to not spam the rpmlint log.

dist/obs-rpmlintrc

@@ -8,3 +8,4 @@ addFilter('zero-length')
 addFilter('files-duplicate')
 addFilter('script-without-shebang')
 addFilter('devel-file-in-non-devel-package')
+addFilter('unexpanded-macro')