compose: Add more space around compose stream privacy icons.
compose: Add more space around compose stream privacy icons.

This is especially to add more space around the globe icon since
it wider than lock icon, so the previously set padding for the
stream icon has to be increased.

andersk/zulip,kou/zulip,zulip/zulip,kou/zulip,kou/zulip,rht/zulip,andersk/zulip,kou/zulip,zulip/zulip,andersk/zulip,rht/zulip,zulip/zulip,zulip/zulip,kou/zulip,zulip/zulip,kou/zulip,andersk/zulip,zulip/zulip,rht/zulip,rht/zulip,rht/zulip,rht/zulip,zulip/zulip,rht/zulip,andersk/zulip,andersk/zulip,kou/zulip,andersk/zulip