tests: don't skip 'ConstantinopleFix' fixtures.

Author: veox

tests/json-fixtures-over-rpc/test_rpc_fixtures.py

@@ -394,8 +394,8 @@ async def validate_uncles(rpc, block_fixture, at_block):
 @pytest.fixture
 def chain_fixture(fixture_data):
     fixture = load_fixture(*fixture_data)
-    if fixture['network'] == 'ConstantinopleFix':
-        pytest.skip('Petersburg VM rules not yet supported')
+    if fixture['network'] == 'Istanbul':
+        pytest.skip('Istanbul VM rules not yet supported')
     return fixture