GUACAMOLE-249: Do not draw background for glyphs when "redundant" (transparent).
GUACAMOLE-249: Do not draw background for glyphs when "redundant" (transparent).

mike-jumper/incubator-guacamole-server,glyptodon/guacamole-server,mike-jumper/incubator-guacamole-server,mike-jumper/incubator-guacamole-server,apache/guacamole-server,apache/guacamole-server,apache/guacamole-server,mike-jumper/incubator-guacamole-server,glyptodon/guacamole-server,glyptodon/guacamole-server