The default configuration value for table border width in the Online Editor is ignored.

Steps to reproduce:

1. Configure table border width as per https://github.com/ezsystems/ezplatform-richtext/pull/151, setting a different default_value:

   system    
       admin_group:
           fieldtypes:
               ezrichtext:
                   attributes:
                       table:
                           border: { type: number, default_value: 12 }

1. Create a Content item with a RichText Field and add a table element
2. Click the table element in the elements selector under the RichText Field and click the edit button

Result:
The default border width value is 1, instead of the configured 12.