node tests: Fix missing coverage on stream_data.js.
node tests: Fix missing coverage on stream_data.js.

This fixes a testing coverage regression in
d5f005fd614447d3905372cccd08dc9cd1efee9f.

punchagan/zulip,showell/zulip,andersk/zulip,eeshangarg/zulip,showell/zulip,brainwane/zulip,andersk/zulip,andersk/zulip,kou/zulip,timabbott/zulip,eeshangarg/zulip,zulip/zulip,eeshangarg/zulip,shubhamdhama/zulip,shubhamdhama/zulip,hackerkid/zulip,brainwane/zulip,rht/zulip,rht/zulip,rht/zulip,punchagan/zulip,brainwane/zulip,eeshangarg/zulip,synicalsyntax/zulip,brainwane/zulip,zulip/zulip,timabbott/zulip,shubhamdhama/zulip,punchagan/zulip,timabbott/zulip,synicalsyntax/zulip,hackerkid/zulip,zulip/zulip,hackerkid/zulip,synicalsyntax/zulip,shubhamdhama/zulip,timabbott/zulip,andersk/zulip,timabbott/zulip,brainwane/zulip,hackerkid/zulip,zulip/zulip,andersk/zulip,eeshangarg/zulip,shubhamdhama/zulip,punchagan/zulip,showell/zulip,timabbott/zulip,punchagan/zulip,hackerkid/zulip,kou/zulip,kou/zulip,kou/zulip,brainwane/zulip,rht/zulip,showell/zulip,synicalsyntax/zulip,punchagan/zulip,eeshangarg/zulip,zulip/zulip,shubhamdhama/zulip,brainwane/zulip,synicalsyntax/zulip,shubhamdhama/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,hackerkid/zulip,zulip/zulip,synicalsyntax/zulip,kou/zulip,punchagan/zulip,andersk/zulip,showell/zulip,hackerkid/zulip,rht/zulip,rht/zulip,rht/zulip,showell/zulip,showell/zulip,synicalsyntax/zulip,andersk/zulip,kou/zulip,timabbott/zulip