The test doesn't work properly if the maxscale user doesn't exist and the
key file permissions cannot be given to it. The test should use the
current user as the owner of the file but it turned out that the -u option
is broken.
Extended the test case to make sure the same password with the same
encryption key results in the same hash.
Since most of the time users run MaxScale as the maxscale user, we can
change the ownership of the file when it is being created. This prevents
the need to manually set the permissions after the file is created.
If the user creating the file is root, the ownership change will work but
on the other hand if the user simply has write permission into MaxScale's
files, the ownership change will likely cause an error. This will still be
an improvement as the user will know the file ownership needs to be
changed.
