FreeBSD uses socklen_t since version 4.0, so define NET_SIZE_T

explicitly there. This gets rid of the following warnings:
http_main.c: In function `child_main':
http_main.c:3988: warning: pointer targets in passing arg 3 of `accept' differ in signedness
http_main.c:4138: warning: pointer targets in passing arg 3 of `getsockname' differ in signedness
http_main.c: In function `main':
http_main.c:5091: warning: pointer targets in passing arg 3 of `getpeername' differ in signedness
http_main.c:5098: warning: pointer targets in passing arg 3 of `getsockname' differ in signedness


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@86429 13f79535-47bb-0310-9956-ffa450edef68