Fix typo in en.json (#5313)

i18n/en.json

@@ -2809,7 +2809,7 @@
   },
   {
     "id": "app.import.import_line.null_user.error",
-    "translation": "Import data line has type \"user\" but the user objcet is null."
+    "translation": "Import data line has type \"user\" but the user object is null."
   },
   {
     "id": "app.import.import_line.unknown_line_type.error",