Add a way to disable/enable users (#3056)

If you want to block users without deleting their account, you can now
disable them from the interface.

app/install.php

@@ -224,6 +224,7 @@ function saveStep3() {
 				[
 					'language' => $_SESSION['language'],
 					'is_admin' => true,
+					'enabled' => true,
 				]
 			);
 		} catch (Exception $e) {