Parallels Desktop 9 compatibility

In Parallels Desktop 9 output of 'prlctl list --info --json <uuid>' does not contains word 'INFO' in the start of a line.
So, my edition make this function 'read_settings' workable in both Parallels Desktop 8 and 9 versions

This simple commit fixes issue #12
https://github.com/yshahin/vagrant-parallels/issues/12