nginx: Update zulip.org nginx configuration.
nginx: Update zulip.org nginx configuration.

* Added zulipbot to configuration.
* Added redirect to zulipchat.com for homepage.

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