pbxProject.prototype.addToHeaderSearchPaths #13 issue, still appeared.

```
if (!buildSettings['HEADER_SEARCH_PATHS']) {
buildSettings['HEADER_SEARCH_PATHS'] = [INHERITED];
}
```

This can be changed like this?
```
if (!buildSettings['HEADER_SEARCH_PATHS']
|| buildSettings['HEADER_SEARCH_PATHS'] === INHERITED) {
buildSettings['HEADER_SEARCH_PATHS'] = [INHERITED];
}
```

Start at pbxProject.prototype.addToHeaderSearchPaths and inspect how HEADER_SEARCH_PATHS is handled when it equals INHERITED. Compare the current condition with the proposed change, then verify that this case produces the intended header search paths using the repository's existing checks.

Written by the indexing model from the issue text.