When we have `NO_PROXY=localhost,one.com,two.com,three.com`, then the
current implementation will pass the following to the backend server:
```
localhost|one.com,two.com,three.com
```
This will mean that only `localhost` will bypass the proxy, which is not
what's expected.
This PR fixes this problem, so that the following is sent to the backend
server:
```
localhost|one.com|two.com|three.com
```
This will mean that requests to all four of them, will bypass the proxy,
as expected.
4b6c8568ad