[SECURITY] Fedora 21 Update: patch-2.7.4-1.fc21

The patch program applies diff files to originals. The diff command is used to compare an original to a changed file. Diff lists the changes made to the file. A person who has the original file can then use the patch command with the diff file to add the changes to their original file (patching the file). Patch should be installed because it is a common way of upgrading applications.