[horde] CalDav calendar sync won't work after server change

[Frank Lienhard]

> 
>> [30-Nov-2020 21:10:06] WARNING: [pool www] child 21678 said into stderr:
>> "[30-Nov-2020 21:10:06 Europe/Berlin] PHP Fatal error:  Cannot use
>> result of built-in function in write context in
>> ~pear/php/Archive/Tar.php on line 662
> 
> This is not Horde code, but from PEAR's Archive_Tar package. You can
> remove that package, I don't believe it's required by Horde or any of
> its apps(?)
So I simply delete the Tar.php file?