Log Message:
Update gcalctool-gtk3 to 6.6.1

    * Fix error reporting not working for certain types of error
    * Add shadow around display
    * Remove reference to removed source file
    * Replace lex/bison parser with hand-written parser
    * Use g_warning not g_error when unable to parse currency file
    * Set window icon correctly
    * Port to GtkApplication
    * Replace menubar with a GMenu
    * Only show thousands separators in decimal mode
    * Translation updates
(unimpressed by https://bugzilla.gnome.org/show_bug.cgi?id=670098)