patch 8.1.0236: Ruby build fails when ruby_intern is missing

Problem:    Ruby build fails when ruby_intern is missing.
Solution:   Do not use ruby_intern2. (Ken Takata)
diff --git a/src/version.c b/src/version.c
index f93e099..ec097fd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    236,
+/**/
     235,
 /**/
     234,