flat:vv changed into fixed

# text = 卒然問曰

1	卒	卒	VERB	v,動詞,変化,生物	_	4	advmod	_	Gloss=end|SpaceAfter=No

2	然	然	VERB	v,動詞,描写,態度	_	1	flat:vv	_	Gloss=like-this|SpaceAfter=No

2	然	然	PART	p,接尾辞,*,*	_	1	fixed	_	Gloss=[suffix]|SpaceAfter=No

3	問	問	VERB	v,動詞,行為,伝達	_	4	advmod	_	Gloss=ask|SpaceAfter=No

4	曰	曰	VERB	v,動詞,行為,伝達	_	0	root	_	Gloss=say|SpaceAfter=No