Fix invocation of VM with spaces in path
Fix invocation of VM with spaces in path

Without this patch, it is not possible to pass a VM path containing spaces to smalltalkCI, like here in mingw:

```
$ smalltalkci -s Squeak64-Trunk --vm "/c/Program Files (x86)/Squeak/SqueakConsole.exe"
```

For more information, see: https://github.com/koalaman/shellcheck/wiki/SC2124
hpi-swa/smalltalkCI,hpi-swa/smalltalkCI