Add Fedora support for Apache 2

The diskimage-builder's fedora element now (as of 1c132f6a) contains the
necessary package mappings, making apache2 compatible with fedora.

Change-Id: I3a66e1791502aba9f2e603544ac0bed6be9ba024
Signed-off-by: Tomas Sedovic <tomas@sedovic.cz>