Add another pattern to "stale connection" detector.

This is fragile, but we don't really want to add a dependency on a concrete
MySQL JDBC library here and then test for some specific internal MySQL JDBC
exception subclass.

src/main/java/com/samskivert/depot/impl/jdbc/MySQLLiaison.java

@@ -32,7 +32,8 @@ public class MySQLLiaison extends BaseLiaison
         String msg = sqe.getMessage();
         return (msg != null && (msg.indexOf("Lost connection") != -1 ||
                                 msg.indexOf("link failure") != -1 ||
-                                msg.indexOf("Broken pipe") != -1));
+                                msg.indexOf("Broken pipe") != -1) ||
+                                msg.indexOf("The last packet successfully received") != -1);
     }
 
     @Override // from DatabaseLiaison