A few small fixes

- Fix race condition in draw_peer()
- Handle realloc_peer_list() error
- Remove dead code in cmd_conference()
- Reduce scope of a few variable variables
- Fix possible buffer truncation in api.c

src/audio_call.c

@@ -916,7 +916,7 @@ void stop_current_call(ToxWindow *self)
  */
 static void realloc_calls(uint32_t n)
 {
-    if (n <= 0) {
+    if (n == 0) {
         free(CallControl.calls);
         CallControl.calls = NULL;
         return;