missing SetForbiddenChars call

Change-Id: I03a26d49210c3dfe89abd31e5c754fafe2b7acee
(cherry picked from commit f219ec6b5e09b55466ce313d73929670cf11a989)
Resolves: #i125086# correct implementation of css::text::XTextField...

in Writer to reflect changes made for the in-place editing of Input Fields

(cherry picked from commit 90b633455a6e54300330e68e71e22e729b445f31)

Conflicts:
	sw/source/core/txtnode/atrfld.cxx
	sw/source/core/unocore/unofield.cxx

Change-Id: I39de2b5074c2e7d8671ad2c0a3c01a29ccfc7882
(cherry picked from commit 41d43bc95b64e1907709141fcd8b6ce08b0841c8)