www/nextcloud: Update to 10.0.0

• Update to new major release 10.0.0
• Add upgrade instruction to pkg-message
• Fix mode on .htaccess / .user.ini [1]
• Switch USE_OPENSSL to USES= ssl
• Update pkg-plist for new version

PR: 211102
Submitted by: Josh Ruehlich <joshruehlig@gmail.com> [1]
Reported by: Josh Ruehlich <joshruehlig@gmail.com> [1]
Approved by: Loic Blot <loic.blot@unix-experience.fr>
MFH: 2016Q3