Merge branch 'fix_mpi_kl' into 'NIFTy_5'

Fix mpi kl

See merge request !366
9 jobs for more_operator_checks in 7 minutes and 39 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build Docker
passed build_docker_from_cache #962582

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  Test
passed test_mpi #962584

00:05:05

passed test_serial #962583

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82.0%
 
  Demo Runs
passed run_bernoulli #962589

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passed run_curve_fitting #962590

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passed run_getting_started_1 #962586

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passed run_getting_started_2 #962587

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passed run_getting_started_3 #962588

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passed run_ipynb #962585

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