Correctly mention previous copyright

[erikjohnston]

During the migration the automated script to update the copyright headers accidentally got rid of some of the existing copyright lines. Reinstate them.

[reivilibre]

curl https://patch-diff.githubusercontent.com/raw/element-hq/synapse/pull/16820.patch > /tmp/patch

rei@lithium:~$ </tmp/patch egrep '^\+' | egrep -v '^\+(\+\+|#| \*)'
+def main():
+    lines = open("licenses").readlines()
+
+    for line in lines:
+        filename, notice = line.split(":", 1)
+
+        pl = open(filename).readlines()
+
+        for line_number, line in enumerate(pl):
+            if line.startswith("# Copyright"):
+                break
+        else:
+            raise Exception(f"Could not find copyright line in {filename}")
+
+        pl.insert(line_number, notice)
+
+        open(filename, "w").writelines(pl)
+
+
+if __name__ == "__main__":
+    main()
+Fixup copyright lines in file headers after the licensing change.

rei@lithium:~$ </tmp/patch egrep '^-' | egrep -v '^-(--)'
-def main():
-    lines = open("licenses").readlines()
-
-    for line in lines:
-        filename, notice = line.split(":", 1)
-
-        pl = open(filename).readlines()
-
-        for line_number, line in enumerate(pl):
-            if line.startswith("# Copyright"):
-                break
-        else:
-            raise Exception(f"Could not find copyright line in {filename}")
-
-        pl.insert(line_number, notice)
-
-        open(filename, "w").writelines(pl)
-
-
-if __name__ == "__main__":
-    main()

Seems legit.