Better handle [No Subject] emails

[saranshdhingra]

Sometimes a user might forget to type a subject and then send the email.

Since Zoho UI allows the user to update the subject before sending, it should be updated within our records as well.

2 Approches:
1: Recognize that the subject has been updated and then show a notification to the user to ask him if he wants to update the subject in our records.

2: Attach an event handler to the confirmation box to call insert_tracker instead of the 'Send' button when th subject is empty.