settings_users: Remove /json/users calls.
settings_users: Remove /json/users calls.

As part of a refactoring, we are now able to remove the
/json/users calls and get all the information needed on people.js.

To do this, now the populate_users uses the people api to get
all the active and non active human users.

punchagan/zulip,rht/zulip,hackerkid/zulip,shubhamdhama/zulip,punchagan/zulip,kou/zulip,zulip/zulip,brainwane/zulip,punchagan/zulip,showell/zulip,punchagan/zulip,brainwane/zulip,andersk/zulip,timabbott/zulip,zulip/zulip,showell/zulip,eeshangarg/zulip,zulip/zulip,brainwane/zulip,hackerkid/zulip,timabbott/zulip,brainwane/zulip,synicalsyntax/zulip,synicalsyntax/zulip,showell/zulip,rht/zulip,shubhamdhama/zulip,showell/zulip,showell/zulip,brainwane/zulip,hackerkid/zulip,kou/zulip,rht/zulip,eeshangarg/zulip,shubhamdhama/zulip,rht/zulip,zulip/zulip,rht/zulip,showell/zulip,hackerkid/zulip,synicalsyntax/zulip,timabbott/zulip,andersk/zulip,zulip/zulip,kou/zulip,synicalsyntax/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,synicalsyntax/zulip,shubhamdhama/zulip,rht/zulip,shubhamdhama/zulip,kou/zulip,eeshangarg/zulip,eeshangarg/zulip,kou/zulip,andersk/zulip,andersk/zulip,rht/zulip,andersk/zulip,punchagan/zulip,synicalsyntax/zulip,timabbott/zulip,eeshangarg/zulip,synicalsyntax/zulip,timabbott/zulip,hackerkid/zulip,timabbott/zulip,zulip/zulip,shubhamdhama/zulip,hackerkid/zulip,showell/zulip,andersk/zulip,brainwane/zulip,brainwane/zulip,shubhamdhama/zulip,kou/zulip,zulip/zulip,punchagan/zulip,timabbott/zulip,eeshangarg/zulip,andersk/zulip,hackerkid/zulip