Disable unused argument warning for 'key_file' in devicelibs.crypto methods
Disable unused argument warning for 'key_file' in devicelibs.crypto methods

This argument was reintroduced in anaconda commit
f988a656cbc7b26a8f9ddca3bfaefa82d7a0aeb9
but was left unused at that time, so I assume was setting up for future
use.

Signed-off-by: mulhern <7b51bcf507bcd7afb72bf8663752c0ddbeb517f6@redhat.com>

dwlehman/blivet,dwlehman/blivet,rhinstaller/blivet,rhinstaller/blivet,rvykydal/blivet,vpodzime/blivet,rvykydal/blivet,vpodzime/blivet,AdamWill/blivet,vojtechtrefny/blivet,vojtechtrefny/blivet,AdamWill/blivet,jkonecny12/blivet,jkonecny12/blivet