patch 8.2.3582: reading uninitialized memory when giving spell suggestions

Problem:    Reading uninitialized memory when giving spell suggestions.
Solution:   Check that preword is not empty.
diff --git a/src/version.c b/src/version.c
index 7bb4236..73ba32e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3582,
+/**/
     3581,
 /**/
     3580,