[Consensus] Bury segwit deployment

Hardcode segwit deployment height to 481824 for mainnet.

test/functional/test_framework/util.py

@@ -342,10 +342,6 @@ def delete_cookie_file(datadir):
         logger.debug("Deleting leftover cookie file")
         os.remove(os.path.join(datadir, "regtest", ".cookie"))
 
-def get_bip9_status(node, key):
-    info = node.getblockchaininfo()
-    return info['softforks'][key]['bip9']
-
 def softfork_active(node, key):
     """Return whether a softfork is active."""
     return node.getblockchaininfo()['softforks'][key]['active']