fix(ui): guard terminal writes while suspended

We forgot to guard `beep()` and `flush()`.

Ref: 36ec2b0ae1
Ref: dd76f9087f
Signed-off-by: Michael Vetter <jubalh@iodoru.org>
Fixes: https://github.com/profanity-im/profanity/issues/2162
(cherry picked from commit 5e4b5d313a9e055e039e2feb4efae58b6aaead78)

src/ui/privwin.c

@@ -57,7 +57,7 @@ privwin_incoming_msg(ProfPrivateWin* privatewin, ProfMessage* message)
         privatewin->unread++;
 
         if (prefs_get_boolean(PREF_FLASH)) {
-            flash();
+            ui_flash();
         }
     }
 
@@ -65,7 +65,7 @@ privwin_incoming_msg(ProfPrivateWin* privatewin, ProfMessage* message)
     wins_add_quotes_ac(window, message->plain, TRUE);
 
     if (prefs_get_boolean(PREF_BEEP)) {
-        beep();
+        ui_beep();
     }
 
     if (notify) {