[tunnelbroker] Remove repeated Dockerfile instructions

Summary:
Packages are installed in tunnelbroker Dockerfile which are already
installed in the base image.

Follow-up to D3268.

Test Plan: npm run build-all in services

Reviewers: ashoat, geekbrother, karol-bisztyga, varun, palys-swm

Reviewed By: palys-swm

Subscribers: Adrian, atul, benschac

Differential Revision: https://phabricator.ashoat.com/D3457