node tests: Fix zjquery leaks in stream_list.
node tests: Fix zjquery leaks in stream_list.

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