test: Don't enforce BIP94 on regtest unless specified by arg

The added regtest option -test=bip94 is only used in the functional
test for BIP94.
This is done because the default regtest consensus rules
should aim to follow to mainnet, not testnet.

test/functional/mining_basic.py

@@ -122,6 +122,7 @@ class MiningTest(BitcoinTestFramework):
     def test_timewarp(self):
         self.log.info("Test timewarp attack mitigation (BIP94)")
         node = self.nodes[0]
+        self.restart_node(0, extra_args=['-test=bip94'])
 
         self.log.info("Mine until the last block of the retarget period")
         blockchain_info = self.nodes[0].getblockchaininfo()