Fix the problem that the function of forcing the plain text response to json is invalid.

[ipcjs]

New Pull Request Checklist

• [x] I have read the Documentation
• [x] I have searched for a similar pull request in the project and found none
• [x] I have updated this branch with the latest develop to avoid conflicts (via merge from master or rebase)
• [x] I have added the required tests to prove the fix/feature I am adding
• [ ] I have updated the documentation (if necessary)
• [x] I have run the tests and they pass