Fixed ImapEngine.Inbox for servers that use INBOX as the namespace
Fixed ImapEngine.Inbox for servers that use INBOX as the namespace

Thanks to @joancaron for this fix (issue #37)

eino-makitalo/MailKit,sstraus/MailKit,jamie-dainton/MailKit,jstedfast/MailKit,nachocove/MailKit,FubarDevelopment/MailKit,dsbenghe/MailKit,matt2003/MailKit,rajeshwarn/MailKit,mganss/MailKit