Remove bigquery ignore tag for ConnectionInfo

[cristinaleonr]

This PR removes the bigquery:"-" tag from the ConnectionInfo field.

Because this optional field was to be ignored by BQ, it caused a fatal error in the Gardener in an instance where it was included in the json file and BQ did not recognize the field.

20220806:ndt/ndt7 Load {Location: "gs://etl-mlab-oti/ndt/ndt7/2022/08/06/20220806T040510.251033Z-ndt7-mlab2-gru02-ndt.tgz.json"; Message: "Error while reading data, error message: JSON parsing error in row starting at position 951624: No such field: raw.Download.ClientMeasurements.ConnectionInfo. File: gs://etl-mlab-oti/ndt/ndt7/2022/08/06/20220806T040510.251033Z-ndt7-mlab2-gru02-ndt.tgz.json"; Reason: "invalid"}

This change is 

[coveralls]

Pull Request Test Coverage Report for Build 1583

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.2%) to 81.504%

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Files with Coverage Reduction	New Missed Lines	%
ndt7/upload/sender/sender.go	5	65.91%

Totals
Change from base Build 1579:	-0.2%
Covered Lines:	1767
Relevant Lines:	2168

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💛 - Coveralls

[stephen-soltesz]

Please add a PR description explaining why we have made this change; this write up may be helpful for future source archeology. Can be briefl.

Reviewed 1 of 1 files at r1.
Reviewable status: complete! 1 of 1 approvals obtained

[cristinaleonr]

Added.

Reviewable status: complete! 1 of 1 approvals obtained

[stephen-soltesz]

Related to: https://github.com/m-lab/dev-tracker/issues/731