Ambiguous Call Error
On Windows 10
When trying to compile and run example_01_basic_app.nim I get this error.
```
C:\Users\Stromberg\.nimble\pkgs\nigui-0.1.1\nigui\private\windows\platform_impl.nim(32, 27) Error: ambiguous call; both strutils.strip(s: string, leading: bool, trailing: bool, chars: set[char])[declared in ..\..\..\..\C:\nim\lib\pure\strutils.nim(391, 5)] and unicode.strip(s: string, leading: bool, trailing: bool, runes: openarray[Rune])[declared in ..\..\..\..\C:\nim\lib\pure\unicode.nim(1892, 5)] match for: (string)
```

Nim version:
```
Nim Compiler Version 0.19.4 [Windows: amd64]
Compiled at 2019-02-01
Copyright (c) 2006-2018 by Andreas Rumpf
```