patch 8.2.4745: using wrong flag for using bell in the terminal

Problem:    Using wrong flag for using bell in the terminal.
Solution:   Change to use BO_TERM.
diff --git a/src/terminal.c b/src/terminal.c
index 9f9e84a..658d5e0 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -3391,7 +3391,7 @@
     static int
 handle_bell(void *user UNUSED)
 {
-    vim_beep(BO_SH);
+    vim_beep(BO_TERM);
     return 0;
 }