Change other instance of Humbug to Zulip in legal notice
Change other instance of Humbug to Zulip in legal notice

vishwesh3/zulip-android,Sam1301/zulip-android,saketkumar95/zulip-android,abhaymaniyar/zulip-android,Sam1301/zulip-android,prati0100/zulip-android,zulip/zulip-android,prati0100/zulip-android,saketkumar95/zulip-android,abhaymaniyar/zulip-android