pyrepl/unix_eventqueue.py: Fix Python 3 ord(char) issue

In Python 3, byte strings are composed of ints, so no need to call ord() on the
elements. Solves a test failure:

    testing/test_unix_reader.py:11: in test_simple
    >           q.push(c)
    pyrepl/unix_eventqueue.py:103: in push
    >       self.buf.append(ord(char))
    E       TypeError: ord() expected string of length 1, but int found

Author: msabramo

pyrepl/unix_eventqueue.py

@@ -100,7 +100,8 @@ def insert(self, event):
         self.events.append(event)
 
     def push(self, char):
-        self.buf.append(ord(char))
+        ord_char = char if isinstance(char, int) else ord(char)
+        self.buf.append(ord_char)
         if char in self.k:
             if self.k is self.ck:
                 #sanity check, buffer is empty when a special key comes