If the case stated by the initial pleading is not removable, a notice of removal may be filed within thirty days after receipt by the defendant, through service or otherwise, of a copy of an amended pleading, motion, order or other paper from which it may first be ascertained that the case is one which is or has become removable, except that a case may not be removed on the basis of jurisdiction conferred by section
1332 of this title more than 1 year after commencement of the action.