dialog-invoice

[Robert Fewell]

I have noticed some invalid casts which trace back to dialog-invoice but
not sure what has changed, so here is what I have found...

Looking at a local pre gtk3/master dialog-invoice.glade, you have
page_terms_menu being a GtkEntry and dialog_terms_menu being a GtkComboBox
with no Entry.

Looking at master now dialog-invoice.glade, you have page_terms_menu being
a GtkComboBox with no Entry and dialog_terms_menu being a GtkComboBox with
no Entry.

What I do not know is did I make a mistake in the conversion, seems strange
I would of changed widgets or was there a change made that was not correct ?

Tried looking at the history of dialog-invoice.glade on GitHub but that has
no history before the directory changes, any other way to find out
what/when changed ?

Bob