RTF import: fix as-char anchored OLE objects

Regression from 2a35f5c7945d00b6f6e21fc7cf5b05b184eba88f (DOCX OLE
import: inherit anchor type from replacement graphic, 2014-02-18), then
problem was that dmapper expected that the anchor type of the
replacement graphic is set, but the RTF tokenizer wasn't adapted to
fulfill this requirement.

Change-Id: I0f7e1a71052f337793d6f844fe5476c3868c03f4