mypy: Clarify types in add_missing_messages in soft_deactivation.py.
mypy: Clarify types in add_missing_messages in soft_deactivation.py.

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