confirmation: Remove generate_activation_url.
confirmation: Remove generate_activation_url.

Wasn't being used outside the file, the URL is specific to
ConfirmationManager, and it makes
EmailChangeConfirmationManager.get_activation_url more obviously parallel
to ConfirmationManager.get_activation_url.

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