recent_topics: Expand width at 767px instead of 700px.
recent_topics: Expand width at 767px instead of 700px.

This looks nice and doesn't break anything.

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