blktap: Really fix changelog

Signed-off-by: Euan Harris <euan.harris@citrix.com>
rpm/configure: Initialize repository metadata in SRPMS directory

We now generate repository metadata after building SRPMs - this
change silences a warning about missing metadata printed because
the metadata does not exist and can't be updated after the first
SRPM is built.

Signed-off-by: Euan Harris <euan.harris@citrix.com>