Replace spaces in short license names with dashes.
Fixed-Lintian-Issues:
 source: space-in-std-shortname-in-dep5-copyright creative commons attribution share-alike (cc-by-sa) v3.0 [debian/copyright:9]
 source: space-in-std-shortname-in-dep5-copyright creative commons attribution share-alike (cc-by-sa) v3.0 [debian/copyright:29]
