Removes the subtitle field from the submission configurator as this has been deprecated. En/disabling it does not have any impact on the submission fields as is. This was a phantom tickbox.

Author: S-Haime

src/submission/models.py

@@ -3284,7 +3284,6 @@ class SubmissionConfiguration(models.Model):
     competing_interests = models.BooleanField(default=True)
     comments_to_the_editor = models.BooleanField(default=True)
 
-    subtitle = models.BooleanField(default=False)
     abstract = models.BooleanField(default=True)
     language = models.BooleanField(default=True)
     license = models.BooleanField(default=True)