Better fix for #865 / differentiate between remote cdx + local WARCs and remote cdx + liveweb loader

[ikreymer]

The fix is to be more concretely differentiate between these two configurations:

# remote cdx + remote proxy loading via LiveWebLoader
remote: cdx+https://remote-archive.example.com/web/cdx

# remote cdx + but *local* WARC loading:
local_coll:
    index_paths: cdx+http://outbackcdx:8080/coll
    archive_paths: /path/to/mywarcs/

The former is for proxying via remote CDX while the latter is the recommend config for OutbackCDX

These supersedes the fix proposed in #917 by adding a conditional to check which configuration is used
(remote cdx + local loading or remote cdx + remote liveweb loading) by checking if archive_paths was provided,
as is needed for usage with OutbackCDX

The skipping of the livewebloader
is needed to be able to retry the lookup path again for revisit records, while of course remote proxying
will not need to do that.

Fixes #865

Screenshots (if appropriate):

Types of changes

• Replay fix (fixes a replay specific issue)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added or updated tests to cover my changes.
• All new and existing tests passed.

[tw4l]

Makes sense and testing well!