configure: fix formatting of missing pkg-config modules error
configure: fix formatting of missing pkg-config modules error

It adds an empty space after the package version.  Previously the error
message looked like:

"You must install the dbus-1 >= 1.0.0pkg-config module to compile libvirt"

Signed-off-by: Giuseppe Scrivano <20002b7b24c75512093a71a58285826d5c504fca@redhat.com>

libvirt/libvirt,zhlcindy/libvirt-1.1.4-maintain,olafhering/libvirt,agx/libvirt,agx/libvirt,eskultety/libvirt,rlaager/libvirt,shugaoye/libvirt,olafhering/libvirt,VenkatDatta/libvirt,agx/libvirt,agx/libvirt,datto/libvirt,zippy2/libvirt,jardasgit/libvirt,crobinso/libvirt,jardasgit/libvirt,andreabolognani/libvirt,crobinso/libvirt,libvirt/libvirt,datto/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,libvirt/libvirt,taget/libvirt,taget/libvirt,eskultety/libvirt,cbosdo/libvirt,zippy2/libvirt,taget/libvirt,andreabolognani/libvirt,rlaager/libvirt,zippy2/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,jardasgit/libvirt,elmarco/libvirt,datto/libvirt,jardasgit/libvirt,cbosdo/libvirt,elmarco/libvirt,andreabolognani/libvirt,olafhering/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jardasgit/libvirt,rlaager/libvirt,cbosdo/libvirt,taget/libvirt,jfehlig/libvirt,taget/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,datto/libvirt,elmarco/libvirt,rlaager/libvirt,elmarco/libvirt,cbosdo/libvirt,zhlcindy/libvirt-1.1.4-maintain,libvirt/libvirt,crobinso/libvirt,nertpinx/libvirt,andreabolognani/libvirt,nertpinx/libvirt,rlaager/libvirt,shugaoye/libvirt,andreabolognani/libvirt,crobinso/libvirt,nertpinx/libvirt,elmarco/libvirt,shugaoye/libvirt,eskultety/libvirt,VenkatDatta/libvirt,datto/libvirt,jfehlig/libvirt,cbosdo/libvirt,eskultety/libvirt,zhlcindy/libvirt-1.1.4-maintain,olafhering/libvirt,nertpinx/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,nertpinx/libvirt,zippy2/libvirt,eskultety/libvirt,fabianfreyer/libvirt,shugaoye/libvirt,agx/libvirt,zhlcindy/libvirt-1.1.4-maintain