debian.package.unsafe: Create missing empty folder not in git

git wont keep track of empty folders, therefore create it using the
Makefile.

debian.package.unsafe/Makefile

@@ -16,6 +16,8 @@ unsafe-boot-metadata-collect-agent/usr/share/initramfs-tools/scripts/local-botto
 		exit 1; \
 	fi
 
+	mkdir -p unsafe-boot-metadata-collect-agent/usr/share/initramfs-tools/scripts/local-bottom
+
 	echo "$${initramfs_script}" >> $@
 
 unsafe-boot-metadata-collect-agent/sbin/metadata-collect-agent: