Update URLs in pom.xml to fix a security issue and to avoid redirects

[stweil]

[stweil]

See https://lgtm.com/projects/g/mguessan/davmail/ for a list of the current LGTM alerts.

[mguessan]

Changed most links from http to https, don't have access to lgtm alerts can you please check ?

[stweil]

I updated the pull request and fixed the merge conflicts.

[stweil]

Changed most links from http to https, don't have access to lgtm alerts can you please check ?

There remains one link which is still reported and will be fixed by this pull request.

LGTM is down since December 2022. It was replaced by the GitHub CodeQL action which can be enabled for each repository in the security settings and which produces the same report.

[mguessan]

Merged in 6.2.0, thanks for your contribution