Remove setting up of auth.type config in gerrit container

gerrit container's docker file was setting auth.type configuration in
gerrit.config file. Depends-on docker tests is using upstream gerrit
image which is using docker volumes for mounting path "/var/gerrit/etc,
this is the path where gerrit.config resides.

As per the Docker documentation at [1] If any build steps change the
data within the volume after it has been declared, those changes
will be discarded, hence remove setting up auth.type config in gerrit
Dockerfile.

[1] https://docs.docker.com/engine/reference/builder/#notes-about-specifying-volumes

Change-Id: Ie8bbc744c6d48281b798bfa23370f396020f093a
1 file changed