Codechange: Suppress warnings when asserts are disabled

src/3rdparty/squirrel/squirrel/sqstate.cpp

@@ -450,7 +450,7 @@ void RefTable::Resize(SQUnsignedInteger size)
 	SQUnsignedInteger oldnumofslots = _numofslots;
 	AllocNodes(size);
 	//rehash
-	SQUnsignedInteger nfound = 0;
+	[[maybe_unused]] SQUnsignedInteger nfound = 0;
 	for(SQUnsignedInteger n = 0; n < oldnumofslots; n++) {
 		if(type(t->obj) != OT_NULL) {
 			//add back;

src/engine.cpp

@@ -538,7 +538,7 @@ void SetupEngines()
 	_engine_pool.CleanPool();
 
 	assert(_engine_mngr.size() >= _engine_mngr.NUM_DEFAULT_ENGINES);
-	uint index = 0;
+	[[maybe_unused]] uint index = 0;
 	for (const EngineIDMapping &eid : _engine_mngr) {
 		/* Assert is safe; there won't be more than 256 original vehicles
 		 * in any case, and we just cleaned the pool. */