firewall4: fix syntax error in dependency spec

Fixes: ae60af8572 ("firewall4: order DEPENDS alphabetically")
Signed-off-by: Jo-Philipp Wich <[email protected]>

package/network/config/firewall4/Makefile

@@ -21,7 +21,7 @@ define Package/firewall4
   SECTION:=net
   CATEGORY:=Base system
   TITLE:=OpenWrt 4th gen firewall
-  DEPENDS:=+ \
+  DEPENDS:= \
 	+kmod-nft-core +kmod-nft-fib +kmod-nft-offload \
 	+kmod-nft-nat +kmod-nft-nat6 \
 	+nftables-json \