Use `prereg.users.set()` in do_invite_users.
Use `prereg.users.set()` in do_invite_users.

This is a bit more idiomatic for many-to-many relationships.

punchagan/zulip,showell/zulip,showell/zulip,eeshangarg/zulip,eeshangarg/zulip,timabbott/zulip,zulip/zulip,brainwane/zulip,rishig/zulip,Galexrt/zulip,shubhamdhama/zulip,shubhamdhama/zulip,amanharitsh123/zulip,Galexrt/zulip,kou/zulip,timabbott/zulip,rishig/zulip,eeshangarg/zulip,tommyip/zulip,showell/zulip,dhcrzf/zulip,Galexrt/zulip,brockwhittaker/zulip,verma-varsha/zulip,brainwane/zulip,rishig/zulip,timabbott/zulip,rishig/zulip,rht/zulip,zulip/zulip,hackerkid/zulip,synicalsyntax/zulip,shubhamdhama/zulip,brainwane/zulip,synicalsyntax/zulip,shubhamdhama/zulip,punchagan/zulip,hackerkid/zulip,hackerkid/zulip,showell/zulip,synicalsyntax/zulip,brockwhittaker/zulip,mahim97/zulip,hackerkid/zulip,rishig/zulip,zulip/zulip,dhcrzf/zulip,kou/zulip,synicalsyntax/zulip,brainwane/zulip,verma-varsha/zulip,rht/zulip,andersk/zulip,kou/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,eeshangarg/zulip,Galexrt/zulip,mahim97/zulip,tommyip/zulip,dhcrzf/zulip,mahim97/zulip,jackrzhang/zulip,jackrzhang/zulip,hackerkid/zulip,rht/zulip,showell/zulip,mahim97/zulip,punchagan/zulip,verma-varsha/zulip,brockwhittaker/zulip,dhcrzf/zulip,verma-varsha/zulip,brainwane/zulip,zulip/zulip,andersk/zulip,Galexrt/zulip,shubhamdhama/zulip,rht/zulip,hackerkid/zulip,andersk/zulip,mahim97/zulip,amanharitsh123/zulip,kou/zulip,Galexrt/zulip,synicalsyntax/zulip,showell/zulip,brockwhittaker/zulip,rht/zulip,Galexrt/zulip,tommyip/zulip,dhcrzf/zulip,andersk/zulip,brockwhittaker/zulip,jackrzhang/zulip,zulip/zulip,synicalsyntax/zulip,tommyip/zulip,brainwane/zulip,rht/zulip,dhcrzf/zulip,mahim97/zulip,showell/zulip,punchagan/zulip,amanharitsh123/zulip,rishig/zulip,amanharitsh123/zulip,amanharitsh123/zulip,timabbott/zulip,amanharitsh123/zulip,shubhamdhama/zulip,verma-varsha/zulip,timabbott/zulip,dhcrzf/zulip,tommyip/zulip,punchagan/zulip,andersk/zulip,rht/zulip,tommyip/zulip,jackrzhang/zulip,tommyip/zulip,timabbott/zulip,brainwane/zulip,punchagan/zulip,rishig/zulip,kou/zulip,verma-varsha/zulip,zulip/zulip,andersk/zulip,zulip/zulip,timabbott/zulip,eeshangarg/zulip,eeshangarg/zulip,jackrzhang/zulip,jackrzhang/zulip,jackrzhang/zulip,andersk/zulip,kou/zulip,brockwhittaker/zulip,hackerkid/zulip,synicalsyntax/zulip,shubhamdhama/zulip