fabfile: add yasm build dependency

Signed-off-by: Sage Weil <sage@inktank.com>
rpm-autosign.exp:  Disable timeout

On loaded gitbuilders it was taking longer than the default timeout
of 10 seconds to get the prompt for the pass phrase. This change
disables the timout.

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>