BiblioAddsAuthorities improvement/fix

BiblioAddsAuthorities improvement/fix

this commit restore a better behaviour :
- if ON : the librarian can enter manually an authority-linked marc field. and if it does not exist in the authorities file, it will be created automatically
- if OFF : the authority must exist in the authority file, and the librarian can't enter if manually in the MARC editor

This patch just deals with the OFF case (the ON was already here). With OFF the behaviour is now the same as in 2.2

Signed-off-by: Joshua Ferraro <jmf@liblime.com>