patch 8.0.0191: can't build with Ruby on some systems

Problem:    Some systems do not have ruby_sysinit(), causing the build to
            fail.
Solution:   Clean up how ruby_sysinit() and NtInitialize() are used. (Taro
            Muraoka)
diff --git a/src/version.c b/src/version.c
index 2094db7..bf4b82d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    191,
+/**/
     190,
 /**/
     189,