Revert "Workaround broken set request in many2many."

When setting eg. groups in users, that would break.

This reverts commit 0e81aa86fbc0c58a08902556b44e1e1dcc9eddab.

bzr revid: p_christ@hol.gr-20090128073444-vufwtd0q79cppqq0

bin/osv/fields.py

@@ -515,9 +515,6 @@ class many2many(_column):
             return
         obj = obj.pool.get(self._obj)
         for act in values:
-	    if not isinstance(act,tuple):
-		print("incorrect values passed in many2many.set:",values)
-		return
             if act[0] == 0:
                 idnew = obj.create(cr, user, act[2])
                 cr.execute('insert into '+self._rel+' ('+self._id1+','+self._id2+') values (%s,%s)', (id, idnew))