Use allocated UID/GID for opensrf in Debian/Ubuntu

I can testify that Debian 9 will not allow you to make a user named opensrf during installation.

After installation if you create the user normally, it does not get the reserved id automatically. In order to use the reserved id, you have to specify it when creating the user.

If you add the opensrf user as a system user, it still does not get the reserved id. In this case, you also have to specify the reserved id.

Since this prevents my usual shortcut of creating the opensrf user during installation, I don't see what advantage this gives us. I now have to do 1 of two things after creating a different user during installation:

1. rename the different user to opensrf
2. create the opensrf user fresh

This adds a step or two to setting up test virtual machines.

Those of us who have systems set up with NFS have to use specific user ids for the opensrf user. If we're expected to switch to a new id, this means changing that user id across all of our systems. Fortunately, this only prevents use of that name during installation. It does not, yet, force the user id created with that name after the fact.

Finally, I don't recall any community discussion of this move. It might have been nice if some public discussion had happened prior to the request being made as this potentially affects all of us.

I want to add that this does not appear to affect Ubuntu. I've had no trouble making the opensrf user during installation on Ubuntu 16.04 or Ubuntu 18.04. I've not tried on Devuan (a Debian derivative), but we don't support Devuan, yet.