Fix _socket compilation failures on non-Linux buildbots (cf. issue #1746656).
diff --git a/configure b/configure
index ae9edce..d5506ef 100755
--- a/configure
+++ b/configure
@@ -6037,7 +6037,7 @@
sys/param.h sys/poll.h sys/select.h sys/sendfile.h sys/socket.h sys/statvfs.h \
sys/stat.h sys/termio.h sys/time.h \
sys/times.h sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h pty.h \
-libutil.h sys/resource.h netpacket/packet.h sysexits.h bluetooth.h \
+libutil.h sys/resource.h net/if.h netpacket/packet.h sysexits.h bluetooth.h \
bluetooth/bluetooth.h linux/tipc.h spawn.h util.h
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`