updated for version 7.3.678
Problem:    Ruby .so name may not be correct.
Solution:   Use the LIBRUBY_SO entry from the config. (Vit Ondruch)
diff --git a/src/configure.in b/src/configure.in
index 4b8c200..8a7de2c 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -1487,7 +1487,7 @@
 	RUBY_PRO="if_ruby.pro"
 	AC_DEFINE(FEAT_RUBY)
 	if test "$enable_rubyinterp" = "dynamic"; then
-	  libruby=`$vi_cv_path_ruby -r rbconfig -e 'printf "lib%s.%s\n", Config::CONFIG[["RUBY_SO_NAME"]], Config::CONFIG[["DLEXT"]]'`
+	  libruby=`$vi_cv_path_ruby -r rbconfig -e 'puts Config::CONFIG[["LIBRUBY_SO"]]'`
 	  AC_DEFINE(DYNAMIC_RUBY)
 	  RUBY_CFLAGS="-DDYNAMIC_RUBY_DLL=\\\"$libruby\\\" -DDYNAMIC_RUBY_VER=$rubyversion $RUBY_CFLAGS"
 	  RUBY_LIBS=