temporarily deactivate some MATE packages unavailable due to RC bugs

mate-sntray-plugin:  https://bugs.debian.org/1086771
mate-applet-appmenu: https://bugs.debian.org/1091049

config/desktop/common/environments/mate/config_base/packages

@@ -86,7 +86,7 @@ lightdm
 lightdm-settings
 lxtask
 mate-accessibility-profiles
-mate-applet-appmenu
+#mate-applet-appmenu
 mate-applet-brisk-menu
 mate-applets
 mate-applets-common
@@ -128,7 +128,7 @@ mate-sensors-applet-common
 mate-session-manager
 mate-settings-daemon
 mate-settings-daemon-common
-mate-sntray-plugin
+#mate-sntray-plugin
 mate-system-monitor
 mate-system-monitor-common
 mate-terminal