chore: fix nice

Author: achingbrain

src/global.cpp

@@ -93,6 +93,8 @@ std::shared_future<void> Cleanup() { return impl::Init::Instance().cleanup(); }
 
 void SetSctpSettings(SctpSettings s) { impl::Init::Instance().setSctpSettings(std::move(s)); }
 
+#if !USE_NICE
+
 UnhandledStunRequestCallback unboundStunCallback;
 
 void InvokeUnhandledStunRequestCallback (const juice_mux_binding_request *info, void *user_ptr) {
@@ -107,6 +109,8 @@ void InvokeUnhandledStunRequestCallback (const juice_mux_binding_request *info,
 	});
 }
 
+#endif
+
 void OnUnhandledStunRequest ([[maybe_unused]] std::string host, [[maybe_unused]] int port, UnhandledStunRequestCallback callback) {
 	#if USE_NICE
 		PLOG_WARNING << "BindStunListener is not supported with libnice, please use libjuice";