Overview of changes in 3.54.9

• Bugs fixed:
  
  • Add DAV detection and configuration for SOGo (Gerald Zehetner)
    
  • #448 DAV discovery fails when certain SRV lookups fail
    

Git-EVTag-v0-SHA512: baac9c7f81eb652471fab3956686ec5908cbfaf2f22101cd04ae84553bc137fe9734ed7170036d3553fbe3af1f65372c1f7891ba07f7fcf5b5e6cbd6d4e0773a