logging: Fix zulip.send_email log being printed in tests.
logging: Fix zulip.send_email log being printed in tests.

Our set_loglevel tool didn't set propagate to False, so just using it
directly wouldn't work unless the logger is explcitly declared in
zproject/settings.py, which this one isn't.

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