patch 8.1.0221: not enough testing for the Ruby interface

Problem:    Not enough testing for the Ruby interface.
Solution:   Add more tests. (Dominique Pelle, closes #3252)
diff --git a/src/version.c b/src/version.c
index d69a8c7..23952a0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -799,6 +799,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    221,
+/**/
     220,
 /**/
     219,