Linux compiler warning

[NickNaso]

On Linux system compiler return these warnings:

../src/deps/nghttp2/lib/nghttp2_helper.c:33:16: warning: implicit declaration of function ‘htons’ [-Wimplicit-function-declaration]
   uint16_t x = htons(n);
                ^~~~~
../src/deps/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_put_uint32be’:
../src/deps/nghttp2/lib/nghttp2_helper.c:38:16: warning: implicit declaration of function ‘htonl’ [-Wimplicit-function-declaration]
   uint32_t x = htonl(n);
                ^~~~~
../src/deps/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_get_uint16’:
../src/deps/nghttp2/lib/nghttp2_helper.c:45:10: warning: implicit declaration of function ‘ntohs’ [-Wimplicit-function-declaration]
   return ntohs(n);
          ^~~~~
../src/deps/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_get_uint32’:
../src/deps/nghttp2/lib/nghttp2_helper.c:51:10: warning: implicit declaration of function ‘ntohl’ [-Wimplicit-function-declaration]
   return ntohl(n);
          ^~~~~

Investigate and try to remove.