Merge #12464: Revert "[tests] bind functional test nodes to 127.0.0.1"

df47afb600 Revert "[tests] bind functional test nodes to 127.0.0.1" (John Newbery)

Pull request description:

  #12200 was merged without test, and breaks `rpc_bind.py`. (Tested locally by @MarcoFalke and me).

  This PR backs out the change.

  Fixes #12462

Tree-SHA512: e92901a0ce05af86486d4f74457953a5502689b03bb2ad9a94f6fd1664385fdda8aa351e601e27ee6580227ea9adb4d7d7fbdc381e69af6b998d9c6f6d358751

test/functional/test_framework/util.py

@@ -292,7 +292,6 @@ def initialize_datadir(dirname, n):
         f.write("port=" + str(p2p_port(n)) + "\n")
         f.write("rpcport=" + str(rpc_port(n)) + "\n")
         f.write("listenonion=0\n")
-        f.write("bind=127.0.0.1\n")
     return datadir
 
 def get_datadir_path(dirname, n):