Merge pull request PyMySQL#204 from bruth/patch-1

Ensure client password defaults to empty string

Author: methane

pymysql/connections.py

@@ -590,7 +590,7 @@ def _config(key, default):
         self.host = host
         self.port = port
         self.user = user or DEFAULT_USER
-        self.password = passwd
+        self.password = passwd or ""
         self.db = database
         self.no_delay = no_delay
         self.unix_socket = unix_socket