Only fetch remote signatures if verification has been enabled, as otherwise the
fetcher throws errors that sstate.bbclass can't ignore.
[ YOCTO #8265 ]
(From OE-Core rev: aa8ba5c4af2636dbc2d0c1ad9c230e8aa26d9962)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>