patch 8.0.1739: MS-Windows with msys2 cannot build Ruby statically

Problem:    MS-Windows with msys2 cannot build Ruby statically.
Solution:   Define RUBY_VERSION. (Gray Wolf, closes #2826)

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1739,
 /**/
     1738,
 /**/