fix headless exception (#3532)
fix headless exception (#3532)


mbenguig/scheduling,ow2-proactive/scheduling,mbenguig/scheduling,fviale/scheduling,ShatalovYaroslav/scheduling,ow2-proactive/scheduling,ShatalovYaroslav/scheduling,fviale/scheduling,ShatalovYaroslav/scheduling,fviale/scheduling,fviale/scheduling,mbenguig/scheduling,ShatalovYaroslav/scheduling,fviale/scheduling,ow2-proactive/scheduling,ShatalovYaroslav/scheduling,mbenguig/scheduling,mbenguig/scheduling,fviale/scheduling,mbenguig/scheduling,ow2-proactive/scheduling,ow2-proactive/scheduling,ShatalovYaroslav/scheduling,ow2-proactive/scheduling,ShatalovYaroslav/scheduling,mbenguig/scheduling,fviale/scheduling,ow2-proactive/scheduling