Link configuration to proper parameter (#5394)

Before, the system configuration was linked to the user parameter while the
user configuration was linked to the system parameter. This was an issue when
trying to retrieve some kind of configuration value in an extension.
Now, the configurations are properly linked to their parameters.

lib/Minz/Extension.php

@@ -231,10 +231,10 @@ abstract class Minz_Extension {
 	/** @param 'system'|'user' $type */
 	private function isExtensionConfigured(string $type): bool {
 		switch ($type) {
-			case 'system':
+			case 'user':
 				$conf = FreshRSS_Context::$user_conf;
 				break;
-			case 'user':
+			case 'system':
 				$conf = FreshRSS_Context::$system_conf;
 				break;
 		}