Fix warning

src/test.cpp

@@ -210,7 +210,9 @@ raii::rjp_ptr read_data_file(const char* file){
 	}
 	blen = fp.length();
 	raii::string buff(blen);
-	fread(buff, blen, 1, fp);
+
+	[[maybe_unused]] size_t ign = fread(buff, blen, 1, fp);
+
 	buff[blen] = 0;
 
 	return raii::rjp_ptr(rjp_parse(buff));