Only add prefixes if list is not empty
Only add prefixes if list is not empty

Fixes an issue for rpm version 4.11 (Relates to Issue #61)

craigwblake/redline,joker1/redline,craigwblake/redline,craigwblake/redline,joker1/redline,joker1/redline,craigwblake/redline,joker1/redline,craigwblake/redline