Webhook fix + documentation fix

Author: jacob1

api.txt

@@ -67,7 +67,7 @@ Request body:
 }
 
 To validate the signature, take the request body as-is (before parsing the json), calculate its SHA-256 hash,
-and then compare that hash to the decrypted hash from the X-Signature request header (base64-decode then decrypt
+and then compare that hash to the decrypted hash from the X-Webhook-Signature request header (base64-decode then decrypt
 using the known public key using ed25519). If any of the following is true, the endpoint should reject the webhook
 and take no action:
 1. Decrypted signature does not match calculated signature
@@ -78,4 +78,4 @@ and take no action:
 The endpoint should return HTTP 200 OK if the webhook is successful and a 4xx or 5xx error code otherwise.
 An optional response body may be sent, but it is currently ignored
 This software does not currently examine or do anything about the error or response body, but that may change
-in the future.
+in the future.

webhook.py

@@ -38,7 +38,7 @@ def send_newpaste(url: str) -> None:
             "nonce": secrets.token_hex(),
             "date": datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S")}
     json_data = json.dumps(data)
-    digest.update(json_data)
+    digest.update(json_data.encode("utf-8"))
     sig = base64.b64encode(key.sign(digest.finalize()))
     headers = {"Content-Type": "application/json; charset=utf-8",
                "X-Webhook-Version": "1.0.0",