Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
index b06077f..d379ba8 100644
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -393,7 +393,7 @@
             else:
                 return data
         except socket.error as why:
-            # winsock sometimes throws ENOTCONN
+            # winsock sometimes raises ENOTCONN
             if why.args[0] in _DISCONNECTED:
                 self.handle_close()
                 return b''