增加公钥Base64的支持

[CC11001100]

比如这个网站：

https://passport.co188.com/sign/signin.html?service=https%3A%2F%2Fwww.co188.com%2F&referer=

它获取公钥的接口：

{
    "code": 0,
    "msg": "success",
    "data": {
        "publickey": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC1HVdLsfBVzD6f04P1nXQRVWG7Rc7HfYx/sXUbH8wMweGiMo8B1ERDrcrD2eAEZASwjU7LMyjVYQK8AjQTPRL2swapBHDfQ34csDe0lIisUG6RYFpczLVGr2Uw65VjqB3kMklKmuLis8JdI0oYq6dpVtj9J7KJpaqwNzkrrmm1RQIDAQAB",
        "rsakey": "dfc0715dffa541c0bc3708a2eefe6bd4"
    }
}

它的publickey就是base64的