compilation with `-lib somelib` uses hxml build file from that lib's folder

How to reproduce
- install git library `haxelib git dragonbones https://github.com/openfl/dragonbones.git` (tested for dragonbones, but any other should work, may be non-git libs work too)
- go to library git folder, e.g. `dragonbones/git`
- create `Main.hx` and `build-test.hxml` files there
```hx
// Main.hx

class Main {
static function main(){
trace('git library');
}
}
```
```hx
# build-test.hxml

-main Main
--interp
```
- now create a folder for new project in some other place
- create `Main.hx` and `build.hxml` in that folder
```hx
// Main.hx

class Main {
static function main() {
trace("actual project");
}
}
```
```hx
# build.hxml

-lib dragonbones
-main Main
--interp
```
- run `build.hxml`

Expected result
```hx
actual project
```
Actual result
```hx
git library
```

If `-lib dragonbones` is commented in `build.hxml` then actual result is equal to expected.

Haxe 4.0.0-preview.5+7eb789f54