Fix server pipeline
Pipeline fails with
[...]
Collecting reportlab (from svglib->sphinx-a4doc)
Downloading https://files.pythonhosted.org/packages/b8/ac/10d68a650b321bd8c4d8cbefd9994e7727d57b381c9bdb0a013273011e62/reportlab-3.6.12.tar.gz (4.5MB)
Complete output from command python setup.py egg_info:
##### -c-python-3.7.3-linux-x86_64: ================================================
##### -c-python-3.7.3-linux-x86_64: Attempting build of _rl_accel
##### -c-python-3.7.3-linux-x86_64: extensions from 'src/rl_addons/rl_accel'
##### -c-python-3.7.3-linux-x86_64: ================================================
##### -c-python-3.7.3-linux-x86_64: ===================================================
##### -c-python-3.7.3-linux-x86_64: Attempting build of _renderPM
##### -c-python-3.7.3-linux-x86_64: extensions from 'src/rl_addons/renderPM'
##### -c-python-3.7.3-linux-x86_64: ===================================================
##### -c-python-3.7.3-linux-x86_64: will use package libart 2.3.21
!!!!! cannot find ft2build.h