Clarion County Economic Development Corporation Executive Director Brad Ehrhart tells us he does not expect that a meeting of local and area government and civic leaders, with Owens-Illinois Company executives, will take place until sometime next week, at the earliest.     It was last Wednesday that O-I disclosed that it close the Clarion plant, this summer.      Fifth Diistrict Congressman Glenn "GT" Thompson tells us he was disappointed to hear of plans to shutdown the local facility.     And, the area lawmaker pledged to do what he can headoff the closing.     Thompson explains that he has already had some contact wih O-I Company officals.