build-appliance-image: Update to walnascar head revision

(From OE-Core rev: 17affdaa600896282e07fb4d64cb23195673baa1)

Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-core/images/build-appliance-image_15.0.0.bb

@@ -26,8 +26,8 @@ inherit core-image setuptools3 features_check
 
 REQUIRED_DISTRO_FEATURES += "xattr"
 
-SRCREV ?= "52b5f6a95de7228a12a9156a4aaa932daf54456f"
-SRC_URI = "git://git.yoctoproject.org/poky;branch=master \
+SRCREV ?= "fd9c569615cf8b463f485faebfabcdcdac0a0018"
+SRC_URI = "git://git.yoctoproject.org/poky;branch=walnascar \
            file://Yocto_Build_Appliance.vmx \
            file://Yocto_Build_Appliance.vmxf \
            file://README_VirtualBox_Guest_Additions.txt \