add condition when we do a virtual-desktops-goto:
If the number for the virtual desktop doesn't exist, we don't setq
virtual-desktops-current.

If we don't respect this condition, the virtual desktop will be block.
Use only spaces for indentation
Merge branch 'master' of https://github.com/chep/virtual-desktops.el

Conflicts:
	virtual-desktops.el