patch 8.2.4068: Vim9: import test fails

Problem:    Vim9: import test fails.
Solution:   Add missing change.
diff --git a/src/scriptfile.c b/src/scriptfile.c
index 9488666..3508139 100644
--- a/src/scriptfile.c
+++ b/src/scriptfile.c
@@ -1274,7 +1274,8 @@
 
     // See if we loaded this script before.
     sid = find_script_by_name(fname_exp);
-    if (sid > 0 && ret_sid != NULL)
+    if (sid > 0 && ret_sid != NULL
+			  && SCRIPT_ITEM(sid)->sn_state != SN_STATE_NOT_LOADED)
     {
 	// Already loaded and no need to load again, return here.
 	*ret_sid = sid;