authority.v2: optimize code paths (raw_result, nonce)

raw_result does not need an extra return, dicarding the nonce at that
point would discard the newer nonce from the response and also the first
nonce is gotten implicitly with the first request acme anyway

acertmgr/authority/v2.py

@@ -42,7 +42,7 @@ class ACMEAuthority(AbstractACMEAuthority):
                 "newOrder": "{}/acme/new-order".format(self.ca),
             }
             print("API directory retrieval failed ({}). Guessed necessary values: {}".format(code, self.directory))
-        self._request_endpoint('newNonce')  # cache the first nonce
+        self.nonce = None
 
         # @todo: Add support for key-types other than RSA
         numbers = key.public_key().public_numbers()
@@ -69,11 +69,8 @@ class ACMEAuthority(AbstractACMEAuthority):
         if 'Replay-Nonce' in resp.headers:
             self.nonce = resp.headers['Replay-Nonce']
 
-        if raw_result:
-            return resp.getcode(), resp.read(), resp.headers
-
         body = resp.read()
-        if len(body) > 0:
+        if not raw_result and len(body) > 0:
             try:
                 body = json.loads(body.decode('utf-8'))
             except json.JSONDecodeError as e:
@@ -110,9 +107,6 @@ class ACMEAuthority(AbstractACMEAuthority):
             return self._request_url(url, data, raw_result)
         except IOError as e:
             return getattr(e, "code", None), getattr(e, "read", e.__str__)(), {}
-        finally:
-            # Dispose of nonce after it was used
-            self.nonce = None
 
     # @brief send a request to authority
     def _request_endpoint(self, request, data=None, raw_result=False):