terminate-psql-sessions: Fix shellcheck warnings.
terminate-psql-sessions: Fix shellcheck warnings.

In scripts/setup/terminate-psql-sessions line 5:
    [ "$1" = "`echo -e "$1\n$2" | sort -V | tail -n1`" ]
              ^-- SC2006: Use $(..) instead of legacy `..`.
                          ^-- SC1117: Backslash is literal in "\n". Prefer explicit escaping: "\\n".

In scripts/setup/terminate-psql-sessions line 20:
major=$(echo $version | cut -d. -f1,2)
             ^-- SC2086: Double quote to prevent globbing and word splitting.

In scripts/setup/terminate-psql-sessions line 24:
tables=$(echo "'$@'" | sed "s/ /','/g")
                ^-- SC2145: Argument mixes string and array. Use * or separate argument.

Signed-off-by: Anders Kaseorg <087231934ba8fcf78bc142ce37d193b895ac03c4@mit.edu>

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