Register Nano Contract lost in infinity loading

[alexruzenhack]

@andreabadesso has found that sometimes the "Register Nano Contract" screen get lost in the loading feedback despite the success in registering the Nano Contract.

[alexruzenhack]

The following PR will fix the infinity loading, however without address the cause: #552

[alexruzenhack]

I've found that this issue is caused when we use the nano-testnet network and the latest version of wallet-lib. The explanation for this issue is that nano-testnet provides the endpoint nano_contract/blueprint while the wallet-lib calls nano_contract/blueprint/info. This mismatch in the endpoint prevents the wallet mobile to download blueprint information, which is necessary to show the nano contract request.

[alexruzenhack]

It is solved when using the staging.nano-testnet.hathor.network server.