notify_new_user: Remove call to statsd.gauge.
notify_new_user: Remove call to statsd.gauge.

This has been deprecated by our analytics system.

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