Add user-agent header to internal requests from RESTBase
Add user-agent header to internal requests from RESTBase

For better internal tracking.

Change-Id: I880005f6d22fb376b7c7aa205d5fd06937c69396

wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps