Janusec/janusec: backend/destination.go; 12 LoC

Found a possible issue in [Janusec/janusec](https://www.github.com/Janusec/janusec) at [backend/destination.go](https://github.com/Janusec/janusec/blob/a146c9317593f643ee9beb4eef4e5d7b4a2d0e95/backend/destination.go#L34-L45)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first issue it finds, so please do not limit your consideration to the contents of the below message.

> range-loop variable dest used in defer or goroutine at line 37

[Click here to see the code in its original context.](https://github.com/Janusec/janusec/blob/a146c9317593f643ee9beb4eef4e5d7b4a2d0e95/backend/destination.go#L34-L45)

Click here to show the 12 line(s) of Go which triggered the analyzer.

```go
for _, dest := range app.Destinations {
if dest.RouteType == models.ReverseProxyRoute && dest.Online == false {
go func() {
conn, err := net.DialTimeout("tcp", dest.Destination, time.Second)
if err == nil {
defer conn.Close()
dest.Online = true
dest.CheckTime = nowTimeStamp
}
}()
}
}

```

Leave a reaction on this issue to contribute to the project by classifying this instance as a **Bug** :-1:, **Mitigated** :+1:, or **Desirable Behavior** :rocket:
See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: a146c9317593f643ee9beb4eef4e5d7b4a2d0e95

Start with backend/destination.go at lines 34-45 and inspect how the goroutine uses dest after the range loop begins. Confirm the analyzer's concern against the surrounding destination-checking flow; done means the goroutine operates on the intended destination for each iteration without changing the check's behavior.

Written by the indexing model from the issue text.