Do not convert to array Process->setInput()

[refsz]

Corrects the problem introduced #646

Closes #646

[samsonasik]

I think definition should be the other way around, instead of define the excluded method, define the will be processed method instead, so new method will not automatically transformed

[samsonasik]

I verified that pass array on setInput() will got error:

 "Symfony\Component\Process\Process::setInput" only accepts strings, Traversable objects or stream resources. 

[samsonasik]

Thank you @refsz