Geotrek-admin 2.77.3

Minor improvements

• Add only_filters filter api v2 for labels (#3002)
• Add filter labels_exclude in api v2, allowing to exclude particular label on treks, sites

Bug fixes

• Fix parser biodiv didn't collect all sensitive areas (#2966)
• Fix attachments external links (#3001)

Maintenance

• Update to paperclip 2.4.1