patch 9.0.0834: warning for missing return type

Problem:    Warning for missing return type.
Solution:   Add "int". (San James, closes #11496)
diff --git a/src/auto/configure b/src/auto/configure
index bcb40a7..644daae 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -12420,7 +12420,7 @@
 /* end confdefs.h.  */
 
 #include <signal.h>
-test_sig()
+int test_sig()
 {
     struct sigcontext *scont;
     scont = (struct sigcontext *)0;