Revert "tests: Support calling add_nodes more than once"

This reverts commit 98a1846.

test/functional/test_framework/test_framework.py

@@ -292,8 +292,7 @@ def add_nodes(self, num_nodes, extra_args=None, *, rpchost=None, binary=None):
         assert_equal(len(extra_args), num_nodes)
         assert_equal(len(binary), num_nodes)
         for i in range(num_nodes):
-            numnode = len(self.nodes)
-            self.nodes.append(TestNode(numnode, get_datadir_path(self.options.tmpdir, numnode), rpchost=rpchost, timewait=self.rpc_timewait, bitcoind=binary[i], bitcoin_cli=self.options.bitcoincli, mocktime=self.mocktime, coverage_dir=self.options.coveragedir, extra_conf=extra_confs[i], extra_args=extra_args[i], use_cli=self.options.usecli))
+            self.nodes.append(TestNode(i, get_datadir_path(self.options.tmpdir, i), rpchost=rpchost, timewait=self.rpc_timewait, bitcoind=binary[i], bitcoin_cli=self.options.bitcoincli, mocktime=self.mocktime, coverage_dir=self.options.coveragedir, extra_conf=extra_confs[i], extra_args=extra_args[i], use_cli=self.options.usecli))
 
     def start_node(self, i, *args, **kwargs):
         """Start a bitcoind"""