Speed up test_socket_error_dupe and test_socket_error_default tests (#573)

Controller.start() starts a thread and waits for a ready event
for 5 seconds (aiosmtpd.controller.DEFAULT_READY_TIMEOUT).
If the thread hits an exception, the ready event never comes.
The `test_socket_error_dupe` and `test_socket_error_default` tests
exercise this scenario, and so each takes full 5 seconds to run.
I updated these two tests to pass in a shorter ready_timeout value
so they don't hang for as long. This saves ~9 seconds for
a full test suite run, per environment.

Author: cuu508

aiosmtpd/tests/test_server.py

@@ -213,7 +213,10 @@ def test_reuse_loop(self, temp_event_loop):
     @pytest.mark.skipif(in_wsl(), reason="WSL prevents socket collision")
     def test_socket_error_dupe(self, plain_controller, client):
         contr2 = Controller(
-            Sink(), hostname=Global.SrvAddr.host, port=Global.SrvAddr.port
+            Sink(),
+            hostname=Global.SrvAddr.host,
+            port=Global.SrvAddr.port,
+            ready_timeout=0.5,
         )
         expectedre = r"error while attempting to bind on address"
         try:
@@ -225,7 +228,10 @@ def test_socket_error_dupe(self, plain_controller, client):
     @pytest.mark.skipif(in_wsl(), reason="WSL prevents socket collision")
     def test_socket_error_default(self):
         contr1 = Controller(Sink())
-        contr2 = Controller(Sink())
+        contr2 = Controller(
+            Sink(),
+            ready_timeout=0.5,
+        )
         expectedre = r"error while attempting to bind on address"
         try:
             with pytest.raises(socket.error, match=expectedre):