patch 9.0.0233: removing multiple text properties takes many calls

Problem:    Removing multiple text properties takes many calls.
Solution:   Pass a list to prop_remove(). (Ben Jackson, closes #10945)
diff --git a/src/version.c b/src/version.c
index 0943fc1..92b55ee 100644
--- a/src/version.c
+++ b/src/version.c
@@ -732,6 +732,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    233,
+/**/
     232,
 /**/
     231,