fix barfing on certain weird scriptsigs (#1263)
fix barfing on certain weird scriptsigs (#1263)

* fix barfing on certain weird scriptsigs

- things that looked kinda like multisigs where redeemscript had only one push
- things that looked kinda like multisigs but redeemscript wasn't multisig.

Generally this code looks like garbage, so we just fail safe to unknown
address for these exceptions (and others that likely exist!)

fixes #1260

* Added a diagnostic print message as defensive programming

fyookball/electrum,fyookball/electrum,fyookball/electrum