fullscreen: fix typo introduced in 5b24bb55ea

Fix #39
library: fix warning when opening an album while in artist view

While browsing the library in "Artist view", opening an album from any
artist used to display in the console a warning such as:

   Gtk-CRITICAL **: gtk_icon_set_render_icon_pixbuf: assertion `icon_set != NULL' failed

and the crumb displaying the album label would not show any icon.
Add CHANGELOG for 0503f3