fix dict.update

Author: hyperbora

Lib/test/test_dict.py

@@ -138,8 +138,6 @@ def test_clear(self):
 
         self.assertRaises(TypeError, d.clear, None)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_update(self):
         d = {}
         d.update({1:100})

vm/src/obj/objdict.rs

@@ -92,7 +92,7 @@ impl PyDict {
                 let iter = objiter::get_iter(vm, &dict_obj)?;
                 loop {
                     fn err(vm: &VirtualMachine) -> PyBaseExceptionRef {
-                        vm.new_type_error("Iterator must have exactly two elements".to_owned())
+                        vm.new_value_error("Iterator must have exactly two elements".to_owned())
                     }
                     let element = match objiter::get_next_object(vm, &iter)? {
                         Some(obj) => obj,