patch 9.0.0841: deletebufline() does not always return 1 on failure

Problem:    deletebufline() does not always return 1 on failure.
Solution:   Refactor the code to make it work more predictable. (closes #11511)
diff --git a/src/version.c b/src/version.c
index e7dc5a5..0e59a78 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    841,
+/**/
     840,
 /**/
     839,