Update guests app #289

WHAT Needs to be Documented?

The guest app needs an update, see owncloud/guests#495 (allow setting share block domains in admin panel)

WHERE Does This Need To Be Documented (Link)?

https://doc.owncloud.com/server/10.9/admin_manual/configuration/user/guests_app.html

WHY Should This Change Be Made?

App update

(Optional) What Type Of Content Change Is This?

• New Content Addition
• Old Content Deprecation
• Existing Content Simplification
• Bug Fix to Existing Content

(Optional) Which Manual Does This Relate To?

• Admin Manual
• Developer Manual
• User Manual
• Android
• iOS
• Branded Clients
• Desktop Client
• Other