Fix error when verifying timestamp that file gzipped by nginx

[fujimotodaisuke]

Purpose

Fix error when verifying timestamp that file gzipped by nginx

Changes

Fix error when verifying timestamp that file gzipped by nginx

QA Notes

• Does this change require a data migration? If so, what data will we migrate?
• What is the level of risk?
  • Any permissions code touched?
  • Is this an additive or subtractive change, other?
• How can QA verify? (Through UI, API, AdminApp or AdminAdminApp?)
  • If verifying through API, what's the new version? Please include the endpoints in PR notes or Dev docs.
• What features or workflows might this change impact?
• How will this impact performance? -->

Documentation

Side Effects

Ticket

GRDM-39009