Fix #596

[AlxClt]

Proposed changes

Adding the case when pretrain=True and p is not None in BaseXLearner.estimate_ate

Types of changes

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• [x ] Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
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Further comments

This is a very simple fix - should not require additional tests

[CLAassistant]

All committers have signed the CLA.

[jeongyoonlee]

LGTM. Thanks for catching it and fixing it.

[jeongyoonlee]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

acollette seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
You have signed the CLA already but the status is still pending? Let us recheck it.

@AlxClt, can you sign the CLA?

[AlxClt]

@jeongyoonlee , just signed the CLA, thanks for pointing this out!