Upgrade @sentry/browser to 5.10.2

What does this MR do?

Upgrades @sentry/browser to the latest version (as of 2019-12-12), 5.10.2.

Reviewed the changes in their CHANGELOG, I would say there's little to no risk in the upgrade.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers