spec: Update version check for maint Source URL

New maint release version numbers of just A.B.C format, not the old
A.B.C.D format. Adjust the check that dynamically changes the Source
URL for maint releases
Signed-off-by: NCole Robinson <crobinso@redhat.com>
Acked-by: NAndrea Bolognani <abologna@redhat.com>

libvirt.spec.in

@@ -233,7 +233,7 @@ Group: Development/Libraries
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
 URL: http://libvirt.org/
 
-%if %(echo %{version} | grep -o \\. | wc -l) == 3
+%if %(echo %{version} | grep -q "\.0$"; echo $?) == 1
     %define mainturl stable_updates/
 %endif
 Source: http://libvirt.org/sources/%{?mainturl}libvirt-%{version}.tar.xz