patch 8.1.2339: insufficient testing for quickfix

Problem:    Insufficient testing for quickfix.
Solution:   Add a few more tests. (Yegappan Lakshmanan, closes #5261)
diff --git a/src/version.c b/src/version.c
index 67ea6af..17517f5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -738,6 +738,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2339,
+/**/
     2338,
 /**/
     2337,