patch 8.2.5123: using invalid index when looking for spell suggestions

Problem:    Using invalid index when looking for spell suggestions.
Solution:   Do not decrement the index when it is zero.
diff --git a/src/version.c b/src/version.c
index 5411e1c..0a42274 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5123,
+/**/
     5122,
 /**/
     5121,