[services] Fix missing port number in D13881

Summary: On Linear, @varun indicated the the port number could be elided here. Turns out that wasn't true, and we're now seeing issues deploying this update to production. I'm landing this change without review in order to fix production.

Test Plan: Unfortunately, we are testing on prod.

Reviewers: varun

Subscribers: tomek, varun

Differential Revision: https://phab.comm.dev/D13882