ignore errors returned by SetKeepAlive (go-sql-driver#1448)

Signed-off-by: Achille Roussel <achille.roussel@gmail.com>

connector.go

@@ -100,10 +100,7 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 	// Enable TCP Keepalives on TCP connections
 	if tc, ok := mc.netConn.(*net.TCPConn); ok {
 		if err := tc.SetKeepAlive(true); err != nil {
-			// Don't send COM_QUIT before handshake.
-			mc.netConn.Close()
-			mc.netConn = nil
-			return nil, err
+			c.cfg.Logger.Print(err)
 		}
 	}