configure: bump required libgrss version to 0.7
configure: bump required libgrss version to 0.7

and now grss has unversioned pc name

Signed-off-by: Igor Gnatenko <71fb2d16c26f553767b965fdac40e83622cad277@src.gnome.org>

outofbits/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker