(maint) Remove 'create' key for masterhttplog setting

[kylog]

This is the only setting that uses this key, and yet the
webrick setup_logger step already creates the file if needed.
So removing this will allow for some code cleanup in
FileSetting and derived classes.

[kylog]

I wanted to get some comments on this before refactoring FileSetting and friends. Thoughts anyone?

[puppetcla]

CLA signed by all contributors.

[joshcooper]

We were discussing file-based settings today in the PR triage relating to #3045. If you have a file-based setting, e.g. Puppet[:ldapcrtdir], which is external to puppet, e.g. it's not Puppet[:confdir], we don't want puppet to go off and try to create/manage the directory. This is possible today by marking the setting as string-based, modifying the places that use the setting to only use the file/directory if it exists. I think that is preferable than marking the setting as :type => file, :create => false, especially because Puppet::Setting::FileSetting#create_files? only applies to files, but not directories. So 👍

[joshcooper]

@kylog what do you think about ticketing this and cleaning up FileSettings at the same time? If we merge just this, I'm not going to remember to do those other things.

[joshcooper]

ping @kylog

[kylog]

Thanks for the reminder. I created https://tickets.puppetlabs.com/browse/PUP-3817. Not sure if I'm going to circle back to this one super soon (although it should be simple), so I'll just close this PR for now.