mod_http_file_share: Allow 'Authorization' header via CORS (thanks kawaii)

Can't find anything saying anything on whether this is needed or not.
kawaii reported that both Chrome and Firefox complained unless the
header was added to the list of allowed headers.

plugins/mod_http_file_share.lua

@@ -584,6 +584,9 @@ module:provides("http", {
 		streaming_uploads = true;
 		cors = {
 			credentials = true;
+			headers = {
+				Authorization = true;
+			};
 		};
 		route = {
 			["PUT /*"] = handle_upload;