Add check for non-strict checks against openssl_verify return

[mschwager]

The openssl_verify function has the unfortunate interface of returning 1 if the signature is correct, 0 if it is incorrect, and -1 on error. This means if you do a naive comparison like if (!openssl_verify(...)) then errors will make it seem as if verification succeeded. Ideally verification should be done with something like if (openssl_verify(...) !== 1).

It'd be great if parse could detect this!