Switch checkbox styling to new style in #invite.
Switch checkbox styling to new style in #invite.

The checkboxes in invite are now converted in this commit to the new
style.

vabs22/zulip,rht/zulip,dhcrzf/zulip,hackerkid/zulip,dhcrzf/zulip,rht/zulip,vabs22/zulip,dhcrzf/zulip,christi3k/zulip,shubhamdhama/zulip,showell/zulip,j831/zulip,rishig/zulip,zulip/zulip,jphilipsen05/zulip,showell/zulip,shubhamdhama/zulip,ryanbackman/zulip,showell/zulip,kou/zulip,eeshangarg/zulip,jrowan/zulip,brockwhittaker/zulip,hackerkid/zulip,jackrzhang/zulip,andersk/zulip,rht/zulip,mahim97/zulip,mahim97/zulip,ryanbackman/zulip,christi3k/zulip,timabbott/zulip,rht/zulip,Galexrt/zulip,verma-varsha/zulip,christi3k/zulip,brockwhittaker/zulip,tommyip/zulip,rht/zulip,eeshangarg/zulip,vaidap/zulip,punchagan/zulip,zulip/zulip,mahim97/zulip,timabbott/zulip,kou/zulip,j831/zulip,punchagan/zulip,kou/zulip,Galexrt/zulip,rishig/zulip,synicalsyntax/zulip,j831/zulip,tommyip/zulip,punchagan/zulip,jphilipsen05/zulip,jrowan/zulip,zulip/zulip,zulip/zulip,jrowan/zulip,jrowan/zulip,vaidap/zulip,punchagan/zulip,jphilipsen05/zulip,eeshangarg/zulip,vabs22/zulip,dhcrzf/zulip,jackrzhang/zulip,vabs22/zulip,dhcrzf/zulip,synicalsyntax/zulip,rishig/zulip,brainwane/zulip,brockwhittaker/zulip,vaidap/zulip,shubhamdhama/zulip,tommyip/zulip,timabbott/zulip,synicalsyntax/zulip,jackrzhang/zulip,jrowan/zulip,showell/zulip,brainwane/zulip,hackerkid/zulip,ryanbackman/zulip,tommyip/zulip,kou/zulip,amanharitsh123/zulip,shubhamdhama/zulip,timabbott/zulip,kou/zulip,synicalsyntax/zulip,andersk/zulip,brainwane/zulip,brockwhittaker/zulip,Galexrt/zulip,zulip/zulip,punchagan/zulip,jackrzhang/zulip,hackerkid/zulip,punchagan/zulip,vabs22/zulip,amanharitsh123/zulip,christi3k/zulip,christi3k/zulip,jphilipsen05/zulip,amanharitsh123/zulip,dhcrzf/zulip,shubhamdhama/zulip,hackerkid/zulip,jackrzhang/zulip,mahim97/zulip,Galexrt/zulip,brainwane/zulip,vabs22/zulip,verma-varsha/zulip,ryanbackman/zulip,amanharitsh123/zulip,vaidap/zulip,jackrzhang/zulip,brainwane/zulip,dhcrzf/zulip,jphilipsen05/zulip,showell/zulip,showell/zulip,tommyip/zulip,eeshangarg/zulip,timabbott/zulip,andersk/zulip,synicalsyntax/zulip,j831/zulip,kou/zulip,shubhamdhama/zulip,rishig/zulip,tommyip/zulip,timabbott/zulip,Galexrt/zulip,ryanbackman/zulip,synicalsyntax/zulip,vaidap/zulip,andersk/zulip,jrowan/zulip,tommyip/zulip,jackrzhang/zulip,vaidap/zulip,jphilipsen05/zulip,andersk/zulip,ryanbackman/zulip,andersk/zulip,rishig/zulip,rht/zulip,brainwane/zulip,j831/zulip,kou/zulip,eeshangarg/zulip,synicalsyntax/zulip,amanharitsh123/zulip,andersk/zulip,shubhamdhama/zulip,amanharitsh123/zulip,rht/zulip,showell/zulip,Galexrt/zulip,eeshangarg/zulip,zulip/zulip,Galexrt/zulip,timabbott/zulip,j831/zulip,punchagan/zulip,brockwhittaker/zulip,verma-varsha/zulip,verma-varsha/zulip,verma-varsha/zulip,hackerkid/zulip,eeshangarg/zulip,brainwane/zulip,rishig/zulip,mahim97/zulip,rishig/zulip,verma-varsha/zulip,zulip/zulip,hackerkid/zulip,christi3k/zulip,brockwhittaker/zulip,mahim97/zulip