Adding  project_rooter_patterns = ['node_modules/'] to [options] doesn't exclude the node_modules folder from FlyGrep searches
Hi, I'm not completely sure if it's a bug or if I'm missing some detail... But checking the [Advanced Usage ](https://spacevim.org/documentation/#advanced-usage)on the documentation it says that we can make the project ignore certain folders. As I'm working with a node.js project, I want to ignore the `node_modules` folder. So I wrote the following in my `init.toml` file:

```
[options]
    project_rooter_patterns = ['.git/', '_darcs/', '.hg/', '.bzr/', '.svn/', 'node_modules/']
```

However, when I try to do some searches with `SPC s p` it still takes a long time to search words because it's also searching inside the `node_modules` folder.

## Expected behavior

It should completely ignore the `node_modules` folder in `SPC s p` searches.

## The reproduce ways from Vim starting

1. Add the following to the `init.toml` file:

```
[options]
    project_rooter_patterns = ['.git/', '_darcs/', '.hg/', '.bzr/', '.svn/', 'node_modules/']
```

2. Make a search with `SPC s p` and it'll also search inside the `node_modules` folder.



