Fix accrights test, use <sys/socket.h>

build/openldap.m4

@@ -1220,7 +1220,7 @@ dnl ====================================================================
 dnl check for msg_accrights in msghdr
 AC_DEFUN(OL_MSGHDR_MSG_ACCRIGHTS,
  [AC_CACHE_CHECK(msg_accrights in msghdr, ol_cv_msg_accrights,
-   [AC_TRY_COMPILE([#include <socket.h>],
+   [AC_TRY_COMPILE([#include <sys/socket.h>],
 		[struct msghdr m; m.msg_accrightslen=0],
 		ol_cv_msghdr_msg_accrights=yes, ol_cv_msghdr_msg_accrights=no)
 	])