Invert logic

src/freedombone-image-makefile

 SIGNATURE = $(ARCHIVE).sig
 OWNER = 1000
 ifeq ("$CONTINUOUS_INTEGRATION", "")
-	XZ =
-	SIGN =
-else
     XZ = xz --no-warn --verbose --keep --threads=0 -3 $(IMAGE)
     SIGN = -gpg --output $(SIGNATURE) --detach-sig $(ARCHIVE)
+else
+	XZ =
+	SIGN =
 endif
 
 # settings for `make test`