syncthing: add specific USERID

Instead of randomly adding a UID this follows the Gentoo numbering and
uses 499.

Signed-off-by: Paul Spooren <mail@aparcar.org>

utils/syncthing/Makefile

@@ -40,7 +40,7 @@ define Package/syncthing
   DEPENDS:=$(GO_ARCH_DEPENDS)
   SECTION:=utils
   CATEGORY:=Utilities
-  USERID:=syncthing:syncthing
+  USERID:=syncthing=499:syncthing=499
 endef
 
 define Package/syncthing/conffiles