EngineBlock 4.6.2

• Really fix: In Firefox, ensure clicking "Press enter to select" area leads to IdP #196
• Bugfix for Tuple (entity_id,type) should be UNIQUE in sso_provider_roles #160.
• Improved Dutch text for IdP error
• Improved logging: Downgrade removing EB from candidate IdPs list to info (not a significant event)
• Improved image alt tags