Allow editing URLs

[waldyrious]

Currently it's possible to edit a capsule by changing its reoccurrence date and periodicity, but I sometimes need to change the URL itself.

This would be useful in cases where one happens to create a capsule when the URL contained tracking parameters, or because the site/page got redirected to a new location, etc.

[maxlath]

It should already be possible to edit the URL in the advanced mode

or am I missing something?