fix bug in iobber_txt: do guess unknown tags

iobber/iobber_txt.py

@@ -145,7 +145,7 @@ def go():
 					new_asent = corpus2.AnnotatedSentence.wrap_sentence(sent)
 					new_sent = corpus2.AnnotatedSentence.cast_as_sentence(new_asent)
 					# preserve_ambiguity = False
-					tagr.disambiguate_sentence(new_sent)
+					tagr.tag_sentence(new_sent, False)
 					if options.shall_chunk:
 						chunkr.tag_sentence(new_sent)
 					# create a new paragraph with the new sentence