wxPython4 sequels: fix exception in connection dialog, force black text in FBD.
- wxPython4 does not have RemoveSizer in API anymore.
- On GTK3 with dark theme default text colour is white, making it unreadable.
#
# Dockerfile for wxPython3.0 running on python2.7
#
FROM python:2.7-stretch
RUN set -xe \
&& apt-get update \
&& apt-get install -y --no-install-recommends python-wxgtk3.0 python-matplotlib \
&& apt-get install -y --no-install-recommends python-xvfbwrapper xvfb \
&& apt-get clean