adding use flag +gui
GLib-GIO-ERROR **: Settings schema 'org.gnome.system.proxy' is not installed
metasploit + use flag gui need gnome-base/gsettings-desktop-schemas in order to works.
installing gsettings-desktop-schemas then starting msfgui4.4 will works
gui has been removed in newer versions and 4.4 is going to be cleaned soon.
please use armitage