Merge branch 'master_fix_update-copyright' into 'master'

fix update-copyright when there is only year without author

See merge request qt-kde-team/qt6/qt6-base!1

debian/scripts/update-copyright

@@ -108,6 +108,7 @@ def parse_file(filename):
         if match:
             copyright = match.group(1)
             max_year = min_year = int(copyright[:4])
+            if len(copyright) >= 5:
                 if copyright[4] == '-':
                     max_year = int(copyright[5:9])
                     author = copyright[10:]
@@ -116,6 +117,8 @@ def parse_file(filename):
                     author = copyright[12:]
                 else:
                     author = copyright[5:]
+            else:
+                author = ""
             author = canonicalize_author_name(author)
             authors.append((min_year, max_year, author))
         match = header_re.search(line)