Runtime: wx.app.mainLoop and twisted reactor now share main thread with runtime.Worker.

This fixes exception when invoking python interactive shell from Runtime's tray
icon right-click menu.

Probably a consequence of wxPython upgrade, together with initial bad idea to
move wx.app.mainloop in non-main thread.

#!/bin/bash

set -e

echo "Building docker image"
docker build \
    --build-arg UID=$(id -u) \
    --build-arg GID=$(id -g) \
    -t beremiz_sikuli .