Use gvir-stream as GVirStream quark name
Use gvir-stream as GVirStream quark name

The previous vir-g-stream name isn't consistent with the naming of
all the other quarks used in libvirt-glib

libvirt/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,libvirt/libvirt-glib,libvirt/libvirt-glib