Error: Illegal URL: about:debugging on restore

[faameunier]

In memory.js:

      logger(this, 'Creating shell tab');
      tab = await browser.tabs.create({ url: restoredTab.full_url, active: false }).catch((error) => {
        logger('Unable to create shell tab !');
        throw error; // should this really hard crash ?
       });

It is illegal in some browser to create pages with some internal url. Example in Firefox:

In such case the link has still disappeared from the front but nothing happens and the information is lost. Related to #95

[faameunier]

109 should do.

We can add forbidden elements as we discover them