sanity: Require minimum of bitbake 2.15.1

This is needed for tinfoil and umask helper function changes.

(From OE-Core rev: d1c39b29f21719b349072c51a761fa19770a49ea)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/conf/sanity.conf

@@ -3,7 +3,7 @@
 # See sanity.bbclass
 #
 # Expert users can confirm their sanity with "touch conf/sanity.conf"
-BB_MIN_VERSION = "2.15.0"
+BB_MIN_VERSION = "2.15.1"
 
 SANITY_ABIFILE = "${TMPDIR}/abi_version"