lint: gofumpt

[serprex]

gofumpt is a stricter superset of gofmt

[lance6716]

  Error: client/example_client_test.go:14:1: File is not properly formatted (gofumpt)
  	//conn, err := client.Connect("127.0.0.1:3306", "root", "", "test", func(c *Conn) {c.UseSSL(true)})
  ^
  Error: client/example_client_test.go:17:1: File is not properly formatted (gofumpt)
  	//tlsConfig := NewClientTLSConfig(caPem, certPem, keyPem, false, "your-server-name")
  ^