cmd_fetch_pack(): declare dest to be const
cmd_fetch_pack(): declare dest to be const

There is no need for it to be non-const, and this avoids the need
for casting away the constness of an argv element.

Signed-off-by: Michael Haggerty <c24c152f145c57791e809b126db9e61bd1c1782d@alum.mit.edu>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git