Overriden `ZKG_DEFAULT_TEMPLATE` ignored if also using `--configfile`

[bbannier]

One should be able to override a configured templates by setting ZKG_DEFAULT_TEMPLATE. This seems not to work when also using --configfile.

Reproducer in zeekurity/zeek:5.0.2 image:

• create a config file

  
  $ zkg config > /tmp/config
  $ cat /tmp/config
  [sources]
  zeek = https://github.com/zeek/packages
  
  [templates]
  default = https://github.com/zeek/package-template
  
  [paths]
  state_dir = /Users/bbannier/.zkg
  script_dir = /usr/local/Cellar/zeek/4.2.2/share/zeek/site
  plugin_dir = /usr/local/Cellar/zeek/4.2.2/lib/zeek/plugins
  bin_dir = /usr/local/Cellar/zeek/4.2.2/bin

• when not using --configfile the value of ZKG_DEFAULT_TEMPLATE is successfully picked up; demonstrated here by passing a path to a non-existing template

  $ ZKG_DEFAULT_TEMPLATE=/tmp/foo zkg create --packagedir=/tmp/bla
  error: problem while loading template /tmp/foo: failed to update template "/tmp/foo": Cmd('git') failed due to: exit code(128)
  cmdline: git clone --recursive /tmp/foo /usr/local/zeek/var/lib/zkg/clones/templates/foo
  stderr: 'fatal: repository '/tmp/foo' does not exist'

• when using --configfile the value of ZKG_DEFAULT_TEMPLATE is not picked up; execution continues with default configured template

  $ ZKG_DEFAULT_TEMPLATE=/tmp/foo zkg --configfile=/tmp/config create --packagedir=/tmp/bla
  "package-template" requires a "name" value (the name of the package, e.g., "FooBar" or "spicy-http"):
  name:

[ckreibich]

Good catch, yep! This is a simple logic bug in zkg's setup. Fix forthcoming.

[ckreibich]

This does not just affect ZKG_DEFAULT_TEMPLATE ... a related problem applies to ZKG_DEFAULT_SOURCE: it just gets ignored:

$ export ZKG_DEFAULT_SOURCE=nonsense
$ zkg refresh
Refresh package source: zeek
        No membership changes
Refresh installed packages
        No new outdated packages

So here it doesn't even matter whether you explicitly provide a config. I'm not sure when this happened, but these are clearly holes in the testsuite. I'll take a look.