Fix HTML report generation

bulk_create.lua

@@ -247,6 +247,7 @@ local function write_reports(player, users, passwords)
 				</body>
 			</html>
 		]]):format(title, title, rows), "\n")
+		file:close()
 	end
 
 	return filename

mod.conf

@@ -3,3 +3,4 @@ name = accountmgr
 author = rubenwardy
 license = MIT
 description = Automatically create accounts in bulk, and export a report to .CSV or .HTML. From .HTML, you can create a .PDF using your web browser.
+min_minetest_version = 5.2