Make roundup-server EACCES errors clearer

If roundup-server is run on a priv port without privs (i.e. non root)
it just returns:

  [Errno 13] Permission denied

make this case clearer by reporting:

  Unable to bind to port 70, access not allowed, errno: 13 Permission denied

so it points to the port bind operation as failing.

Author: rouilj

roundup/scripts/roundup_server.py

@@ -792,6 +792,15 @@ class ThreadingServer(socketserver.ThreadingMixIn,
             if e.args[0] == errno.EADDRINUSE:
                 raise socket.error(_("Unable to bind to port %s, "
                                      "port already in use.") % self["PORT"])
+            if e.args[0] == errno.EACCES:
+                raise socket.error(_("Unable to bind to port %(port)s, "
+                                     "access not allowed, "
+                                     "errno: %(errno)s %(msg)s" % {
+                                         "port": self["PORT"],
+                                         "errno": e.args[0],
+                                         "msg": e.args[1] }
+                ))
+                                     
             raise
         # change user and/or group
         setgid(self["GROUP"])