Fix make distcheck

A file was missing from translations.

Author: info-cppsp

po/POTFILES.in

@@ -67,6 +67,7 @@ plugins/filebrowser/filebrowser.plugin.desktop.in
 plugins/filebrowser/pluma-file-bookmarks-store.c
 plugins/filebrowser/pluma-file-browser-plugin.c
 plugins/filebrowser/pluma-file-browser-store.c
+plugins/filebrowser/pluma-file-browser-utils.c
 plugins/filebrowser/pluma-file-browser-view.c
 plugins/filebrowser/pluma-file-browser-widget.c
 plugins/modelines/modelines.plugin.desktop.in