patch 9.0.1211: storing value in interface member does not always work

Problem:    Storing value in interface member does not always work.
Solution:   Convert the index on the interface to the index on the object.
diff --git a/src/version.c b/src/version.c
index c489dba..a388019 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1211,
+/**/
     1210,
 /**/
     1209,