patch 8.1.1586: error number used in two places

Problem:    Error number used in two places.
Solution:   Renumber one. (Ken Takata)
diff --git a/src/version.c b/src/version.c
index 58bfc1e..9d2f26c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1586,
+/**/
     1585,
 /**/
     1584,