tiny-secp256k1 allows for verify() bypass when running in bundled environment

tiny-secp256k1 is a tiny secp256k1 native/JS wrapper. Prior to version 1.1.7, a malicious JSON-stringifyable message can be made passing on verify(), when global Buffer is the buffer package. This affects only environments where require('buffer') is the NPM buffer package. Buffer.isBuffer check can be bypassed, resulting in strange objects being accepted as a message, and those messages could trick verify() into returning false-positive true values. This issue has been patched in version 1.1.7.