Summary:
Updating the regex to avoid a potential regular expression denial-of-service vulnerability.
Changelog: Update validateBaseUrl to use a more robust regular expression. Fixes CVE-2020-1920, GHSL-2020-293
Reviewed By: lunaleaps
Differential Revision: D25507604
fbshipit-source-id: c36a03c456881bc655c861e1a2c5cd41a7127c9d