correct true/false literal's source
correct true/false literal's source

Before:
        Literal, token: true value: true
           Type: bool
           Source: "true;"

After:
        Literal, token: true value: true
           Type: bool
           Source: "true"

Extra token is removed.

ruchevits/solidity,ruchevits/solidity,ruchevits/solidity,ruchevits/solidity