Attach file button label consistency

[Thijs Triemstra]

On a ticket page the label for the file attach button always reads 'Attach file'. On the attachments page that label always reads 'Attach another file'.

The issue with the 'Attach another file' label is the fact it's always showing, even when there are no attachments, although the label suggests a file was previously attached. A solution would be using the label 'Attach file' when there are 0 attachments, and 'Attach another file' when there are one or more attachments already.

This could also apply to the label on the ticket page.