net/keepalived: preserve keepalived uci file over sysupgrade

Preserve keepalived uci file over sysupgrade.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/keepalived/Makefile

@@ -38,6 +38,7 @@ endef
 
 define Package/keepalived/conffiles
 /etc/keepalived/keepalived.conf
+/etc/config/keepalived
 endef
 
 CONFIGURE_ARGS+= \