Remove label memory_max from BaseRecalibrator process

[maxulysse]

• Remove label memory_max from BaseRecalibrator process to fix BaseRecalibrator is eating up all the memory #72

PR checklist

• This comment contains a description of changes (with reason)
• If you've fixed a bug or added code that should be tested, add tests!
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• Documentation in docs is updated
• CHANGELOG.md is updated
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[szilvajuhos]

Tack, will re-test the whole ICGC once we have enough disk space left (next week maybe)

[apeltzer]

LGTM