Set default value of zero to User submissionLimit

[rosselton]

Summary

The User content type has a field submission Limit, this should be set to zero as a default in Strapi. Currently this is 'null' on submission creation.

What needs to be done?

• check to see if we can set a default value to the field
• if not, make sure the value is set to one successfully on creation

The submission value is updated by one, after a successful submission, but this has not been tested on an initial null value, rather than an integer.