bugfix: prevent array bounds violations due to short WS payload data

Guard against zero-length binary payloads before dereferencing data[0] or data[1]

wled00/ws.cpp

@@ -87,7 +87,8 @@ void wsEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
       } else if (info->opcode == WS_BINARY) {
         // first byte determines protocol. Note: since e131_packet_t is "packed", the compiler handles alignment issues
         //DEBUG_PRINTF_P(PSTR("WS binary message: len %u, byte0: %u\n"), len, data[0]);
-        int offset = 1; // offset to skip protocol byte
+        constexpr int offset = 1; // offset to skip protocol byte
+        if (!data || len < offset+1) return; // catch invalid / single-byte payload
         switch (data[0]) {
           case BINARY_PROTOCOL_E131:
             handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_E131);