Make suggested updates to http11 and http20 constructors

Author: fredthomsen

CONTRIBUTORS.rst

@@ -36,4 +36,4 @@ In chronological order:
 - Fred Thomsen (@fredthomsen)
 
   - Added support for upgrade of plaintext HTTP/1.1 to plaintext HTTP/2.
-
+  - Added proxy support.

hyper/http11/connection.py

@@ -84,13 +84,15 @@ def __init__(self, host, port=None, secure=None, ssl_context=None,
             if proxy_port is None:
                 try:
                     self.proxy_host, self.proxy_port = proxy_host.split(':')
-                    self.proxy_port = int(self.proxy_port)
                 except ValueError:
                     self.proxy_host, self.proxy_port = proxy_host, 8080
+                else:
+                    self.proxy_port = int(self.proxy_port)
             else:
                 self.proxy_host, self.proxy_port = proxy_host, proxy_port
         else:
             self.proxy_host = None
+            self.proxy_port = None
 
         #: The size of the in-memory buffer used to store data from the
         #: network. This is used as a performance optimisation. Increase buffer

hyper/http20/connection.py

@@ -90,13 +90,15 @@ def __init__(self, host, port=None, secure=None, window_manager=None, enable_pus
             if proxy_port is None:
                 try:
                     self.proxy_host, self.proxy_port = proxy_host.split(':')
-                    self.proxy_port = int(self.proxy_port)
                 except ValueError:
                     self.proxy_host, self.proxy_port = proxy_host, 8080
+                else:
+                    self.proxy_port = int(self.proxy_port)
             else:
                 self.proxy_host, self.proxy_port = proxy_host, proxy_port
         else:
             self.proxy_host = None
+            self.proxy_port = None
 
         #: The size of the in-memory buffer used to store data from the
         #: network. This is used as a performance optimisation. Increase buffer