[pkg-horde] php-horde-mnemo is marked for autoremoval from testing

[Debian testing autoremoval watch]

php-horde-mnemo 4.2.14-1 is marked for autoremoval from testing on 2018-01-10

It (build-)depends on packages with these RC bugs:
882916: php-sabre-vobject: php-sabre-vobject FTBFS with phpunit 6.4.4-2
882939: php-sabredav: php-sabredav FTBFS with phpunit 6.4.4-2