sanity.bbclass: mention version when erroring on LCONF_VERSION mismatch

sanity.bbclass: mention version when erroring on LCONF_VERSION mismatch

If someone is using a Poky release but not the Poky distribution they'll get a
bblayers.conf generated from meta-yocto's template with a LCONF_VERSION that
doesn't necessarily match LAYER_CONF_VERSION (default in sanity.conf), as Poky
overrides LAYER_CONF_VERSION to cater for the meta-yocto split.  The resulting
error message will tell them to compare bblayers.conf with bblayers.conf.sample,
but they're identical.

By explicitly refering to the required and actual versions this situation is
hopefully clearer.

(From OE-Core rev: da58843fd07dec43700a4c54ac469d1fda71aa50)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>