patch 9.0.1283: the code for setting options is too complicated

Problem:    The code for setting options is too complicated.
Solution:   Refactor the do_set() function. (Yegappan Lakshmanan, Lewis
            Russell, closes #11945)
diff --git a/src/version.c b/src/version.c
index 2f5e3bf..fb8795b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1283,
+/**/
     1282,
 /**/
     1281,