do not send two PHAs

since with request_pha we send the CertificateRequest always,
if we combine it with `/secret` we end up with two requests

Author: tomato42

scripts/tls.py

@@ -572,7 +572,7 @@ def do_GET(self):
                     else:
                         raise ValueError("Invalid return from "
                                          "send_keyupdate_request")
-            if self.path.startswith('/secret'):
+            if self.path.startswith('/secret') and not request_pha:
                 try:
                     for i in self.connection.request_post_handshake_auth():
                         pass