patch 8.1.1489: sign order wrong when priority was changed

Problem:    Sign order wrong when priority was changed.
Solution:   Reorder signs when priority is changed. (Yegappan Lakshmanan,
            closes #4502)
diff --git a/src/version.c b/src/version.c
index 90ee247..f63c5f3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1489,
+/**/
     1488,
 /**/
     1487,