updated for version 7.3.974
Problem:    Can't build with ruby 1.8.5.
Solution:   Only use ruby_init_stack() when RUBY_INIT_STACK is defined.
            (Yukihiro Nakadaira)
diff --git a/src/version.c b/src/version.c
index f9dd542..6c6b650 100644
--- a/src/version.c
+++ b/src/version.c
@@ -729,6 +729,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    974,
+/**/
     973,
 /**/
     972,