org settings: Fix usage of forEach method on jQuery object.
org settings: Fix usage of forEach method on jQuery object.

Commit 612b237cec847fea1d48c42eaa98baa3744374b8 introduced a
regression that broke the “Discard” button, because
get_subsection_property_elements returns a jQuery object rather than
array, and jQuery objects don’t have a forEach method.  Change it to
return an array.

[dfdb7392591db597bc41cf266a9c3bc12a2706e5@zulipchat.com: Use Array.from instead of .toArray to avoid the
need for extra mocking.]
Signed-off-by: Anders Kaseorg <dfdb7392591db597bc41cf266a9c3bc12a2706e5@zulipchat.com>

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