create-db.sql: Start by dropping the zulip database if needed.

At some point the PostgreSQL Docker image started creating the zulip
database for us, which caused our CREATE DATABASE to fail.

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

scripts/setup/create-db.sql

@@ -1,3 +1,5 @@
+\connect postgres
+DROP DATABASE IF EXISTS zulip;
 DO $$BEGIN
     CREATE USER zulip;
 EXCEPTION WHEN duplicate_object THEN

scripts/setup/postgres-init-db

@@ -44,10 +44,6 @@ source "$(dirname "$0")/terminate-psql-sessions" postgres zulip zulip_base
 # Make sure the current working directory is readable by postgres
 cd /
 
-su "$POSTGRES_USER" -c 'psql -v ON_ERROR_STOP=1 -e' <<EOF
-DROP DATABASE IF EXISTS zulip;
-EOF
-
 su "$POSTGRES_USER" -c 'psql -v ON_ERROR_STOP=1 -e' < "$(dirname "$0")/create-db.sql"
 )