navbar: Remove unnecessary :not() selector.
navbar: Remove unnecessary :not() selector.

Replace not selector with equivalent properties.

zulip/zulip,punchagan/zulip,hackerkid/zulip,kou/zulip,eeshangarg/zulip,andersk/zulip,eeshangarg/zulip,andersk/zulip,punchagan/zulip,rht/zulip,hackerkid/zulip,eeshangarg/zulip,punchagan/zulip,punchagan/zulip,showell/zulip,andersk/zulip,hackerkid/zulip,kou/zulip,punchagan/zulip,andersk/zulip,punchagan/zulip,andersk/zulip,eeshangarg/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,showell/zulip,andersk/zulip,zulip/zulip,kou/zulip,rht/zulip,eeshangarg/zulip,zulip/zulip,showell/zulip,zulip/zulip,zulip/zulip,kou/zulip,hackerkid/zulip,showell/zulip,kou/zulip,rht/zulip,hackerkid/zulip,showell/zulip,rht/zulip,rht/zulip,hackerkid/zulip,kou/zulip,showell/zulip,rht/zulip,kou/zulip,hackerkid/zulip,punchagan/zulip,eeshangarg/zulip,zulip/zulip,andersk/zulip,showell/zulip