VStudio can't open files without .vdb

[jda]

Hi Rualan, I can't log into Mantis anymore, so I'll post this bug here.

VStudio let's you select any file to open, but unless there is a .vdb 
extension I refuses to open it, even if it's a valid Valentina 
database. My databases have a different extension, so this is a real 
nuisance. You already have an example db that I sent you and Ivan 
recently you can see this with -- try to open it with VStudio. Or I 
can send you a new one.

This is with a copy of VStudio I downloaded today, BTW.

Jon