...have data ranges associated with it. Empty charts do not
have data ranges. Reverts the part of

c55d5226

which makes this assumption.

Matching test cases (in uitest) coming up soon in another commit.

Change-Id: I60f0f03a8c937ecfdff95047bdfeeb7733eff4a4
Reviewed-on: https://gerrit.libreoffice.org/40057Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>