transport/pcsc: explicitly specify T0 protocol

From pyscard user's guide [1]:

   == Selecting the card communication protocol ==

   By defaults, the connect() method of the CardConnection object
   will try to connect using either the T=0 or T=1 protocol.
   To force a connection protocol, you can pass the required
   protocol to the connect() method.

This means that a PC/SC ifd handler may automatically choose T=1
as the highest protocol if the card indicates both in its ATR [2].

Since pySim only supports T=0, let's select it explicitly.

[1] https://pyscard.sourceforge.io/user-guide.html
[2] https://github.com/acshk/acsccid/issues/16#issuecomment-501101972

Change-Id: Ifed4574aab98a86c3ebbeb191f36a8282103e775

pySim/transport/pcsc.py

@@ -22,6 +22,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+from smartcard.CardConnection import CardConnection
 from smartcard.CardRequest import CardRequest
 from smartcard.Exceptions import NoCardException, CardRequestTimeoutException
 from smartcard.System import readers
@@ -52,7 +53,10 @@ class PcscSimLink(LinkBase):
 
 	def connect(self):
 		try:
-			self._con.connect()
+			# Explicitly select T=0 communication protocol
+			self._con.connect(CardConnection.T0_protocol)
+		except CardConnectionException:
+			raise ProtocolError()
 		except NoCardException:
 			raise NoCardError()