mypy: Clarify valid types in tornado views via new variable.
mypy: Clarify valid types in tornado views via new variable.

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