Cannot read property 0 of undefined during index update fix

[flyinghuman]

this fixes the error during index update if there are no adresses.

[TheHolyRoger]

@flyinghuman why aren't there any addresses?

Looks like an easy merge but wondering what the cause is, not seen this.

@uaktags have you?

[TheHolyRoger]

Also related to this:
https://github.com/walletbuilders/iquidus-x11-patch/blob/master/iquidus_x11_patch.diff
#286

[TheHolyRoger]

This has been hanging around since #56

I'm just not sure if the fix in this PR is good enough or we need to handle it better?

[uaktags]

It's an easy fix indeed, but the problems seem to be related to coin specific anomalies. It may be more suited to later look into coin-specific parsing objects that we call during these checks. Basically we do checks against what the coin allows, and either skip over all of it to do a save_tx without vins/vouts or proceed with them. Not exactly sure how to do that cleanly though as already just typing it out sounds pretty stupid and intensive of a process for the sync.