Fix compiling of readthedocs after switch to ciecplib
This fixes the failing readthedocs builds: https://readthedocs.org/projects/gwcelery/builds/20096510/
These failures appeared after the commit: ce15c3a3
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This fixes the failing readthedocs builds: https://readthedocs.org/projects/gwcelery/builds/20096510/
These failures appeared after the commit: ce15c3a3