libnftnl: bump to 1.1.5

libnftnl: bump to 1.1.5

Solve missing references to nftnl_set_list_lookup_byname when building
iptables with Nftables support enabled (CONFIG_IPTABLES_NFTABLES)

Bump the ABI version to force everything to match.

/Users/kevin/wrt/staging_dir/toolchain-x86_64_gcc-9.2.0_musl/lib/gcc/x86_64-openwrt-linux-musl/9.2.0/../../../../x86_64-openwrt-linux-musl/bin/ld: xtables_nft_multi-nft-bridge.o: in function `nft_bridge_parse_lookup':
nft-bridge.c:(.text.nft_bridge_parse_lookup+0xcd): undefined reference to `nftnl_set_list_lookup_byname'
/Users/kevin/wrt/staging_dir/toolchain-x86_64_gcc-9.2.0_musl/lib/gcc/x86_64-openwrt-linux-musl/9.2.0/../../../../x86_64-openwrt-linux-musl/bin/ld: xtables_nft_multi-nft-cache.o: in function `nftnl_set_list_cb':
nft-cache.c:(.text.nftnl_set_list_cb+0x80): undefined reference to `nftnl_set_list_lookup_byname'
/Users/kevin/wrt/staging_dir/toolchain-x86_64_gcc-9.2.0_musl/lib/gcc/x86_64-openwrt-linux-musl/9.2.0/../../../../x86_64-openwrt-linux-musl/bin/ld: xtables_nft_multi-nft-cache.o: in function `fetch_set_cache':
nft-cache.c:(.text.fetch_set_cache+0x10a): undefined reference to `nftnl_set_list_lookup_byname'
collect2: error: ld returned 1 exit status
make[6]: *** [xtables-nft-multi] Error 1
make[5]: *** [all] Error 2
make[4]: *** [all-recursive] Error 1
make[3]: *** [all] Error 2
make[2]: *** [/Users/kevin/wrt/build_dir/target-x86_64_musl/linux-x86_64/iptables-1.8.4/.built] Error 2
make[2]: Leaving directory `/Users/kevin/wrt/package/network/utils/iptables'

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>