fetch --prune: always print header url

fetch --prune: always print header url

If "fetch --prune" is run with no new refs to fetch, but it has refs
to prune. Then, the header url is not printed as it would if there were
new refs to fetch.

Output before this patch:

	$ git fetch --prune remote-with-no-new-refs
	 x [deleted]         (none)     -> origin/world

Output after this patch:

	$ git fetch --prune remote-with-no-new-refs
	From https://github.com/git/git
	 x [deleted]         (none)     -> origin/test

Signed-off-by: Tom Miller <jackerran@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>