Remove htonl() Autoconf check (#13627)

The htonl() function is available in libc on current *nix systems. On
Solaris versions around 2.5.1 it was located in the socket library.
Haiku has it in libc and Windows in ws2_32, which is linked as part of
the common libraries. This removes the redundant HAVE_HTONL symbol.

Author: petk

configure.ac

@@ -359,7 +359,6 @@ dnl uClibc will bark at linking with glibc's libnsl.
 
 PHP_CHECK_FUNC(socket, socket, network)
 PHP_CHECK_FUNC(socketpair, socket, network)
-PHP_CHECK_FUNC(htonl, socket, network)
 PHP_CHECK_FUNC(gethostname, nsl, network)
 PHP_CHECK_FUNC(gethostbyaddr, nsl, network)
 AC_SEARCH_LIBS([dlopen], [dl],