patch 9.0.0184: virtual text prop highlight continues after truncation

Problem:    Virtual text prop highlight continues after truncation.
Solution:   Recompute the length of attributes.
diff --git a/src/version.c b/src/version.c
index 582cb36..27503b5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -736,6 +736,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    184,
+/**/
     183,
 /**/
     182,