analytics: Fix type annotation for sql_data_collector.
analytics: Fix type annotation for sql_data_collector.

zulip/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,zulip/zulip,rht/zulip,rht/zulip,zulip/zulip,rht/zulip,andersk/zulip,hackerkid/zulip,zulip/zulip,eeshangarg/zulip,zulip/zulip,kou/zulip,hackerkid/zulip,andersk/zulip,zulip/zulip,kou/zulip,eeshangarg/zulip,hackerkid/zulip,hackerkid/zulip,rht/zulip,hackerkid/zulip,rht/zulip,kou/zulip,kou/zulip,rht/zulip,andersk/zulip,eeshangarg/zulip,kou/zulip,hackerkid/zulip,eeshangarg/zulip,eeshangarg/zulip,hackerkid/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,andersk/zulip,rht/zulip,zulip/zulip,andersk/zulip