Notebook detection fix

[coveralls]

Pull Request Test Coverage Report for Build 4a78f43e-3682-4c22-af71-e0ed6cd919aa

• 6 of 7 (85.71%) changed or added relevant lines in 1 file are covered.
• 105 unchanged lines in 23 files lost coverage.
• Overall coverage increased (+3.9%) to 65.37%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
wandb/lib/ipython.py	6	7	85.71%
<!--	Total:	6	7	85.71%	-->

Files with Coverage Reduction	New Missed Lines	%
wandb/apis/internal_runqueue.py	1	22.42%
wandb/filesync/dir_watcher.py	1	81.62%
wandb/internal/internal_api.py	1	61.36%
wandb/internal/meta.py	1	70.8%
wandb/internal/run.py	1	61.54%
wandb/lib/ipython.py	1	80.0%
wandb/util.py	1	64.75%
tests/test_datastore.py	2	97.83%
tests/test_util.py	2	97.44%
tests/utils/notebook_client.py	2	72.22%
<!--	Total:	105		-->

Totals
Change from base Build e57e652b-af5d-4566-bc49-6b18e7e4926a:	3.9%
Covered Lines:	13961
Relevant Lines:	21357

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💛 - Coveralls