retention: Remove redundant LEFT JOIN in archiving UserMessages.
retention: Remove redundant LEFT JOIN in archiving UserMessages.

zerver_archivedmessage is already INNER JOIN-ed earlier in the query, so
we check the pub_date in it, instead of joining zerver_message, which
would just redundantly join the analogical rows.

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