Sorry about this - I'm looking into it now. I can reproduce here, and I'm pretty sure we'll be able to get the ESP8266 firmware fixed without soldering - this did work in the past so it's likely some change either in esptool or the Espruino firmware.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Sorry about this - I'm looking into it now. I can reproduce here, and I'm pretty sure we'll be able to get the ESP8266 firmware fixed without soldering - this did work in the past so it's likely some change either in esptool or the Espruino firmware.