tmp: reword this later. details on how this was tested below

```
python3 -m http.server 8080 --bind 127.0.0.1
python3 -m http.server 8080 --bind localhost
python3 -m http.server 8080 --bind ::1
python3 -m http.server 8080 --bind ::1
```

and check

```
lsof -Pn | grep -E ':8080'

localias add frontend.local 8080
localias add frontend.testing 8080
```

```
curl 'http://[::]:8080/'
curl 'http://[::1]:8080/'
curl 'http://127.0.0.1:8080/'
curl 'http://localhost:8080/'
curl 'https://frontend.local'
curl 'https://frontend.testing'
```

Author: peterldowns

pkg/config/config.go

@@ -213,7 +213,7 @@ func (entry Entry) Caddyfile() string {
 	}
 	return fmt.Sprintf(strings.TrimSpace(`
 %s {
-	reverse_proxy :%d
+	reverse_proxy localhost:%d
 	%s
 }
 	`), entry.Alias, entry.Port, tls)