Add configure test for the 'sigaction' function.
diff --git a/configure b/configure
index 1bc6fc4..68d2355 100755
--- a/configure
+++ b/configure
@@ -6809,7 +6809,8 @@
 
 
 
-for ac_func in socket inet_aton usleep
+
+for ac_func in socket inet_aton usleep sigaction
 do
 as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
 echo "$as_me:$LINENO: checking for $ac_func" >&5