curl: do not output requirements for files that are local.

Fixes a bug introduced by r12079.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@12105 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=85c434c08985337fa476e56fae0fde3e955dbd73