code such as:
```Nim
import std/httpclient # nim c --hint:performance:on
echo newHttpClient(proxy=nil,
headers=newHttpHeaders({"Accept": "*/*"})).getContent("x")
```
(Fix was suggested by @ringabout in a private channel.)
Seems useful since `httpclient` is so basic/probably pervasive with many
hundreds of `import`s across the NimbleVerse.
c11b3f3fc7