in function MySQLDriver.Open: replace errBadConnNoWrite with driver.E…

…rrBadConn for resend while 'bad connection' happenning

driver.go

@@ -123,7 +123,8 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 	}
 	if err = mc.writeHandshakeResponsePacket(authResp, addNUL, plugin); err != nil {
 		mc.cleanup()
-		return nil, err
+		// errBadConnNoWrite should be replaced with driver.ErrBadConn for resend
+		return nil, mc.markBadConn(err)
 	}
 
 	// Handle response to auth packet, switch methods if possible