nimble config breaks choosenim
I have a nimble config with the following:

```ini
nimbleDir="/home/demi/.nimble/" 

[PackageList]
name="local"
path="/home/demi/.config/nimble/packages.json"
```

this configuration seems to work with nimble, I can search the packages I've added to it and locate them without issue. however, now whenever I run `choosenim`, I get the following error:

```
choosenim.nim(201)       choosenim 
cliparams.nim(134)       newCliParams
config.nim(101)          parseConfig
Error: unhandled exception: Unable to parse config file: Unknown key: path [NimbleError]
```

this seems to trace back to where `choosenim` calls on `nimble` to parse the config file, but comes back as a failure even though the `path` property is a valid and expected property for the additional package list to have. this error happens regardless of command or flags passed to `choosenim`. if I completely comment out the additional `packagelist` section and properties from the `nimble.ini` then `choosenim` operates without issue.

additional info:
nimble version: `nimble v0.9.0 compiled at 2019-01-28 23:13:35 (no git-hash attached)`
choosenim version: `choosenim v0.3.2 (2018-02-28 14:12:37) [linux/amd64]`

additional additional info:
after building `choosenim` from source, the locally built version had no issues with the config, but the binary installed via the install script did; I don't know the significance of this as they are the same version, but figured this might help debug what is going on.