If in Writer dragging the anchor is already active
it is not allowed to enter global object drag mode.
This check was missing and may lead to various
inconsistencies

Change-Id: I7d8dd2a62737e6d5d72f69747ceb21bcb73c45ed
Reviewed-on: https://gerrit.libreoffice.org/38059Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>