Check that msg.To() is not nil in GetVMEnv

[gsalgado]

Otherwise it will panic when msg is creating a contract.

Closes: #50

[jpmsam]

Hi @gsalgado ,

Thank you for the pull request and for your contribution.

We have to send you a CLA to sign, can you please send the email address you'd like to receive it at to quorum_info@jpmorgan.com ?

Also, would you mind sharing the script and steps that you used to replicate issue #50 ?

Thanks,
Sam

[gsalgado]

Hi Sam,

Please send the CLA to guilherme.salgado@consensys.net.

Unfortunately I can't share the code (it's a Go unit test) that triggers #50 as it's a closed project, but basically what it does is use ethclient (via the contract bindings generated by abigen) to deploy a new contract.

Cheers,
Guilherme