patch 9.0.0092: plugins cannot change v:completed_item

Problem:    Plugins cannot change v:completed_item.
Solution:   Make v:completed_item writeable. (Shougo Matsushita,
            closes #10801)
diff --git a/src/version.c b/src/version.c
index 5adb215..4d97dcd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -736,6 +736,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    92,
+/**/
     91,
 /**/
     90,