mypy: Move accidental mock annotation for self.
mypy: Move accidental mock annotation for self.

Curiously, the obviously broken annotation for
self obscured the lack of assert here, so I
fixed that too.

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