fix for partly uninitialized sound sync packets (audioreactive)

audioSyncPacket contains four "invisible" padding bytes added by the compiler. These need to be initialized to zero, as future versions of the protocol will make use of these fields.

Author: softhack007

usermods/audioreactive/audio_reactive.h

@@ -960,6 +960,8 @@ class AudioReactive : public Usermod {
       //DEBUGSR_PRINTLN("Transmitting UDP Mic Packet");
 
       audioSyncPacket transmitData;
+      memset(reinterpret_cast<void *>(&transmitData), 0, sizeof(transmitData)); // make sure that the packet - including "invisible" padding bytes added by the compiler - is fully initialized
+
       strncpy_P(transmitData.header, PSTR(UDP_SYNC_HEADER), 6);
       // transmit samples that were not modified by limitSampleDynamics()
       transmitData.sampleRaw   = (soundAgc) ? rawSampleAgc: sampleRaw;