Fix CC0 license string

penyuan · penyuan · commit b253f40bb752 · 2021-04-01T18:16:14.000+01:00
From `CC0` to `CC0-1.0`
diff --git a/.reuse/dep5 b/.reuse/dep5
@@ -28,4 +28,4 @@ License: CC-BY-4.0
 Files: 
     docs/images/EU_flag.svg
 Copyright: Council of Europe
-License: CC0
+License: CC0-1.0
