Don't verify images with the empty build key
Don't verify images with the empty build key

We replaced the build key with an empty file while compiling shim
for our distro. Skip the verification with the empty build key
since this makes no sense.

Signed-off-by: Gary Ching-Pang Lin <a057d4b27e9e9055b973f54b519db54c22ed5ee8@suse.com>

android-ia/platform_external_uefi_shim,rhinstaller/shim,CyanogenMod/android_external_uefi_shim,rhinstaller/shim,android-ia/platform_external_uefi_shim,CyanogenMod/android_external_uefi_shim,android-ia/platform_external_uefi_shim,rhinstaller/shim,CyanogenMod/android_external_uefi_shim