global_state: remove reload function

Only user can call it upon itself.

src/global_state.py

@@ -38,9 +38,6 @@ class GlobalState:
     def navigate_to_page(self, *args):
         self._uninitialized()
 
-    def reload_page(self, *args):
-        self._uninitialized()
-
     def reload_title_image(self, *args):
         self._uninitialized()
 

src/ui/pages/disk.py

@@ -69,7 +69,7 @@ class DiskPage(Gtk.Stack, Page):
 
     @Gtk.Template.Callback('reload')
     def _reload(self, button):
-        global_state.reload_page()
+        self.load()
 
     ### public methods ###
 

src/ui/window.py

@@ -72,7 +72,6 @@ class OsInstallerWindow(Adw.ApplicationWindow):
         global_state.advance = self.advance
         global_state.retranslate_pages = self.retranslate_pages
         global_state.navigate_to_page = self.navigate_to_page
-        global_state.reload_page = self.reload_page
         global_state.reload_title_image = self._reload_title_image
         global_state.installation_failed = self.show_failed_page