We need to get VCL initialized early in UniPoll mode, since the main
setup doesn't occur until runPoll is invoked, and we want to call lots
of virtual methods that take the SolarMutex before then - which requires
VCL to be initialized.

Change-Id: Id9c1b74c126cf7bb71d6560b7585d37327a9f5ef
Reviewed-on: https://gerrit.libreoffice.org/72071
Tested-by: Jenkins
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>