By Tassilo Hummel PARIS (Reuters) -Parts of a contested new French immigration law go against the constitution and must be scrapped, France’s Constitutional Council said on Thursday. The court, a body that validates the constitutionality of laws, struck down nearly three dozen measures contained in the bill, including the lion’s share of clauses introduced by opposition rightwing lawmakers during a turbulent parliamentary process. Measures including toughening conditions for the family reunification of migrants, birthright citizenship and access to state welfare, were scrapped, mostly for proc…