Remove %LAUNCHER_ARGS% for standalone apps

By default templates will create a web.config `//aspNetCore/@arguments` set to `%LAUNCHER_ARGS%`. publish-iis only touches the processPath attribute. As a result the web.config looks like this: 

```
 <aspNetCore processPath=".\MyApp.exe" arguments="%LAUNCHER_ARGS%" ...
```

On full IIS the arguments are passed verbatim to .MyApp.exe and the app does not start.
