build: Fix uninstall when WITH_APPARMOR_PROFILES is defined

build: Fix uninstall when WITH_APPARMOR_PROFILES is defined

When libvirt configuration includes '--with-apparmor-profiles', the
make uninstall target fails

make[1]: Entering directory '/home/jim/upstream/libvirt/examples'
 ( cd '/etc/apparmor.d//abstractions' && rm -f libvirt-qemu libvirt-lxc )
 ( cd '/etc/apparmor.d/' && rm -f usr.lib.libvirt.virt-aa-helper usr.sbin.libvirtd )
make[1]: *** No rule to make target 'uninstall-apparmor-local', needed by
'uninstall-local'.  Stop.

Add missing 'uninstall-apparmor-local' target to the examples Makefile.am.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>