Fix buffer overrun in `solveOutputScript`

[jahrsg]

pubKeyBuffer was initialized with 256 zeros, but buffers with length 160 are sent to this function.

[linux-mining]

Hi jahrsg. With your changes does this make it to the end of the blockchain? I assume I just remove parser.cpp and util.cpp and replace with with yours and compile?

Anyway, that what I did as the original only made it to ~74% and crashed. Running with your changes now.