zjquery: Fix ‘this’ parameter of invoked handlers.
zjquery: Fix ‘this’ parameter of invoked handlers.

Signed-off-by: Anders Kaseorg <dfdb7392591db597bc41cf266a9c3bc12a2706e5@zulip.com>

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