[iiifdownloader] Add -insecure flag to ignore TLS errors

At the time of writing, the https://manuscrits-france-angleterre.org
website has expired certificates, which make accessing their images
a pain. While the issue is obviously with them, it's reasonable for
us to add a -insecure flag (emphatically not the default) to override
cert checking for cases like this.

0 files changed, 0 insertions, 0 deletions