Fix missing user agent headers to store an empty string rather than null value

Author: DaneEveritt

app/Models/AuditLog.php

@@ -120,8 +120,8 @@ public static function instance(string $action, array $metadata, bool $isSystem
             'server_id' => null,
             'action' => $action,
             'device' => $request ? [
-                'ip_address' => $request->getClientIp(),
-                'user_agent' => $request->userAgent(),
+                'ip_address' => $request->getClientIp() ?? '127.0.0.1',
+                'user_agent' => $request->userAgent() ?? '',
             ] : [],
             'metadata' => $metadata,
         ]);