Merge petertodd#232: Remove wrong text in P2WPKH example explanation

4cc4402 Remove wrong text in P2WPKH example explanation (Bryan Bishop)

Pull request description:

  I think this makes the explanation more correct. There is no such thing as an "implicit template" really.

ACKs for top commit:
  petertodd:
    ACK [4cc4402](petertodd@4cc4402)

Tree-SHA512: 72562c2104c98c60262db3ba3fe2b0216ee08447cdfe0e8d239940372df9db7568bc2f6ede4054bee3bcb1c65783591f17e1ea74595bb32f9a02b243d79a94b5

Author: petertodd

examples/spend-p2wpkh.py

@@ -87,8 +87,8 @@
 # the witness so that the appropriate redeem_script can be calculated by
 # anyone. The original scriptPubKey had only the Hash160 hash of the public
 # key, not the public key itself, and the redeem script can be entirely
-# re-constructed (from implicit template) if given just the public key. So the
-# public key is added to the witness. This is P2WPKH in bip141.
+# re-constructed  if given just the public key. So the public key is added to
+# the witness. This is P2WPKH in bip141.
 witness = [signature, public_key]
 
 # Aggregate all of the witnesses together, and then assign them to the