[bip174] Fix typo in signer pseudo code

Author: lukechilds

bip-0174.mediawiki

@@ -337,7 +337,7 @@ sign_non_witness(script_code, i):
 
 for input,i in enumerate(psbt.inputs):
     if non_witness_utxo.exists:
-        assert(sha256d(non_witness_utxo) == psbt.tx.innput[i].prevout.hash)
+        assert(sha256d(non_witness_utxo) == psbt.tx.input[i].prevout.hash)
         if redeemScript.exists:
             assert(non_witness_utxo.vout[psbt.tx.input[i].prevout.n].scriptPubKey == P2SH(redeemScript))
             sign_non_witness(redeemScript)