broken pipe errors are not treated as driver.ErrBadConnection

[vijay1811]

'write tcp 172.22.6.246:53576-\u003e 172.30.236.26:5432: write: broken pipe' this error is not treated as special error and query to database fails.

[vijay1811]

I think fix could be

case *net.OpError:
		cn.bad = true
		*err = v // - > err  = driver.ErrBadConnection

https://github.com/lib/pq/blob/master/error.go#L497