message: fix char vs str mistake
diff: @@ -189,7 +189,7 @@ void usb_cmd_thread(void const * argument) {
  // Record into parse buffer when actively reading
  if (read_active) {
  parse_buffer[parse_buffer_idx++] = c;
  - if (c == '\r' || c == '\n' || c == "!") {
  + if (c == '\r' || c == '\n' || c == '!') {
  // End of command string: exchange end char with terminating null
  parse_buffer[parse_buffer_idx-1] = '\0';
  motor_parse_cmd(parse_buffer, parse_buffer_idx);
  