patch 9.0.0186: virtual text without highlighting does not show

Problem:    Virtual text without highlighting does not show. (Ben Jackson)
Solution:   Use a text property when it has highlighting or when it has text.
            (closes #10878)
diff --git a/src/version.c b/src/version.c
index eb9566c..6e278e5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -736,6 +736,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    186,
+/**/
     185,
 /**/
     184,