scripted-diff: Remove setup_clean_chain if default is not changed

-BEGIN VERIFY SCRIPT-
git grep -l "self.setup_clean_chain = False" test/functional/*.py | xargs sed -i "/self.setup_clean_chain = False/d";
-END VERIFY SCRIPT-

test/functional/p2p_invalid_locator.py

@@ -13,7 +13,6 @@ from test_framework.test_framework import BitcoinTestFramework
 class InvalidLocatorTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
-        self.setup_clean_chain = False
 
     def run_test(self):
         node = self.nodes[0]  # convenience reference to the node