convert license to SPDX

This is part of https://fedoraproject.org/wiki/Changes/SPDX_Licenses_Phase_4

vapoursynth.spec

@@ -1,8 +1,9 @@
 Name:       vapoursynth
 Version:    68
-Release:    3%{?dist}
+Release:    4%{?dist}
 Summary:    Video processing framework with simplicity in mind
-License:    LGPLv2
+# Automatically converted from old format: LGPLv2 - review is highly recommended.
+License:    LicenseRef-Callaway-LGPLv2
 URL:        http://www.vapoursynth.com
 
 Source0:    https://github.com/%{name}/%{name}/archive/R%{version}/%{name}-R%{version}.tar.gz
@@ -116,6 +117,9 @@ rm -fr %{buildroot}%{_docdir}/%{name}
 %{_bindir}/vspipe
 
 %changelog
+* Wed Sep 04 2024 Miroslav Suchý <msuchy@redhat.com> - 68-4
+- convert license to SPDX
+
 * Sat Jul 20 2024 Fedora Release Engineering <releng@fedoraproject.org> - 68-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild