general: Clean up warnings

src/application.rs

 use crate::config;
 use crate::utils;
 use crate::widgets::Window;
-use gtk::gdk;
 use gtk::gio::{self, prelude::*};
 use gtk::glib::{self, clone};
 use gtk::prelude::*;

src/main.rs

@@ -14,8 +14,14 @@ fn main() {
     pretty_env_logger::init();
     // Prepare i18n
     setlocale(LocaleCategory::LcAll, "");
-    bindtextdomain(GETTEXT_PACKAGE, LOCALEDIR);
-    textdomain(GETTEXT_PACKAGE);
+    bindtextdomain(GETTEXT_PACKAGE, LOCALEDIR).expect(&format!(
+        "Unable to bind text domain for {}",
+        GETTEXT_PACKAGE
+    ));
+    textdomain(GETTEXT_PACKAGE).expect(&format!(
+        "Unable to switch to text domain {}",
+        GETTEXT_PACKAGE
+    ));
 
     glib::set_application_name(&gettext("Tour"));
     glib::set_prgname(Some("Tour"));

src/widgets/window.rs

-use crate::utils::i18n_f;
 use gettextrs::gettext;
 use gtk::glib;
 use gtk::prelude::*;
@@ -96,8 +95,6 @@ impl Window {
             .upcast::<gtk::Widget>(),
         );
 
-        let name = glib::os_info("NAME").unwrap_or_else(|| "GNOME".into());
-        let version = glib::os_info("VERSION").unwrap_or_else(|| "".into());
         let last_page = ImagePageWidget::new(
             "/org/gnome/Tour/ready-to-go.svg",
             gettext("That's it. Have a nice day!"),