Resolves: #i122818# fix crash in online-update-check when no app is active
Resolves: #i122818# fix crash in online-update-check when no app is active

Closing all application windows and retaining access to the application menu
is only possible on MacOSX. The DispatchProvider used for the update check
seems to depend on having an active application window. Maybe it is possible
to get the update check working without it but this patch doesn't attempt
that, it prevent further escalation such as crashes.

Fixed by: Herbert Duerr
Debugged by: Oliver-Rainer Wittmann, Herbert Duerr
Found by: Frantisek Erben

(cherry picked from commit bd363910bb80e61805672430de7870e1583b0052)

Conflicts:
	cui/source/options/optupdt.cxx

Change-Id: I0a00b8a3af8e37997e82ffd325c8239142acbf4a

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core