[dist] Rpmlint: Fix zero-length and version-control-internal-file

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.

Ignoring zero-length solves many warnings caused by the gem sources.

dist/obs-rpmlintrc

@@ -4,3 +4,4 @@ addFilter('no-manual-page-for-binary')
 addFilter('non-executable-script')
 addFilter('no-changelogname-tag')
 addFilter('hidden-file-or-dir')
+addFilter('zero-length')