test_messages: Clean up some slow tests.
test_messages: Clean up some slow tests.

One isn't actually slow; the other was doing something wasteful.

hackerkid/zulip,rht/zulip,punchagan/zulip,jackrzhang/zulip,punchagan/zulip,zulip/zulip,showell/zulip,dhcrzf/zulip,eeshangarg/zulip,showell/zulip,hackerkid/zulip,timabbott/zulip,synicalsyntax/zulip,tommyip/zulip,synicalsyntax/zulip,timabbott/zulip,eeshangarg/zulip,tommyip/zulip,brockwhittaker/zulip,rht/zulip,dhcrzf/zulip,jackrzhang/zulip,rishig/zulip,mahim97/zulip,tommyip/zulip,brainwane/zulip,Galexrt/zulip,shubhamdhama/zulip,kou/zulip,mahim97/zulip,rishig/zulip,kou/zulip,eeshangarg/zulip,kou/zulip,synicalsyntax/zulip,shubhamdhama/zulip,tommyip/zulip,rht/zulip,punchagan/zulip,andersk/zulip,zulip/zulip,brainwane/zulip,mahim97/zulip,dhcrzf/zulip,Galexrt/zulip,zulip/zulip,rishig/zulip,hackerkid/zulip,timabbott/zulip,andersk/zulip,jackrzhang/zulip,Galexrt/zulip,brainwane/zulip,showell/zulip,timabbott/zulip,brainwane/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,hackerkid/zulip,hackerkid/zulip,punchagan/zulip,synicalsyntax/zulip,Galexrt/zulip,mahim97/zulip,punchagan/zulip,brockwhittaker/zulip,shubhamdhama/zulip,kou/zulip,brockwhittaker/zulip,brockwhittaker/zulip,andersk/zulip,jackrzhang/zulip,rishig/zulip,Galexrt/zulip,hackerkid/zulip,rht/zulip,andersk/zulip,shubhamdhama/zulip,shubhamdhama/zulip,dhcrzf/zulip,kou/zulip,eeshangarg/zulip,punchagan/zulip,tommyip/zulip,brockwhittaker/zulip,Galexrt/zulip,rht/zulip,mahim97/zulip,synicalsyntax/zulip,synicalsyntax/zulip,timabbott/zulip,dhcrzf/zulip,timabbott/zulip,rishig/zulip,brainwane/zulip,brainwane/zulip,eeshangarg/zulip,jackrzhang/zulip,andersk/zulip,zulip/zulip,zulip/zulip,synicalsyntax/zulip,tommyip/zulip,eeshangarg/zulip,hackerkid/zulip,andersk/zulip,kou/zulip,jackrzhang/zulip,brainwane/zulip,Galexrt/zulip,dhcrzf/zulip,rht/zulip,timabbott/zulip,showell/zulip,showell/zulip,dhcrzf/zulip,jackrzhang/zulip,rishig/zulip,mahim97/zulip,zulip/zulip,showell/zulip,shubhamdhama/zulip,punchagan/zulip,kou/zulip,tommyip/zulip,showell/zulip,andersk/zulip,brockwhittaker/zulip,shubhamdhama/zulip,rishig/zulip