spec: Support maintenance releases on mingw

The regular spec file contains code to deal with the fact
that maintenance releases are uploaded to their own
directory: copy it over to the mingw spec file so that it's
possible to build maintenance releases there as well.

This also switches the source URL from FTP to HTTP for
consistency with the main spec file.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>

mingw-libvirt.spec.in

@@ -30,7 +30,11 @@ Summary:        MinGW Windows libvirt virtualization library
 License:        LGPLv2+
 Group:          Development/Libraries
 URL:            http://libvirt.org/
-Source0:        ftp://libvirt.org/libvirt/libvirt-%{version}.tar.xz
+
+%if %(echo %{version} | grep -q "\.0$"; echo $?) == 1
+    %define mainturl stable_updates/
+%endif
+Source: http://libvirt.org/sources/%{?mainturl}libvirt-%{version}.tar.xz
 
 BuildRequires:  mingw32-filesystem >= 95
 BuildRequires:  mingw64-filesystem >= 95