Fix regexp for cl.exe
This command returns some special characters preventing regexp to work.

For more details, see:
http://document-foundation-mail-archive.969070.n3.nabble.com/Could-not-determine-MSC-version-Visual-Studio-2017-td4256538.html

Change-Id: I734dcd533b0f38430d1be8852f1e4f721221e580
Reviewed-on: https://gerrit.libreoffice.org/66959
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>