Update Uninstall-ChocolateyPackage.ps1

# I tested this change when uninstalling the NSClient++ Nagios msi package and it worked fine.
# Might not be backward compatible if $file parameter doesn't refer to the actual msi-package used
# when installing.

Uninstall-ChocolateyPackage 'nscp' 'msi' '/passive' <PATH_TO_MSI_FILE>