start: Avoid probing server version with WEBLATE_DATABASES=False

See WeblateOrg/weblate#10037

start

@@ -152,28 +152,39 @@ fi
 
 # Wait for database to get available
 TIMEOUT=0
-until psql -h "$POSTGRES_HOST" -p "$POSTGRES_PORT" -d "$POSTGRES_DATABASE" -U "$POSTGRES_USER" -c 'SELECT 1' > /dev/null ; do
-    >&2 echo "Postgres at ${POSTGRES_HOST:-db} is unavailable - retrying $((30 - TIMEOUT))"
+until run_weblate shell -c 'from weblate.auth.models import User; User.objects.raw("SELECT 1")' > /dev/null ; do
+    >&2 echo "Database server at ${POSTGRES_HOST:-db} is unavailable - retrying $((30 - TIMEOUT))"
     TIMEOUT=$((TIMEOUT + 1))
     if [ $TIMEOUT -gt 30 ] ; then
-        psql -h "$POSTGRES_HOST" -p "$POSTGRES_PORT" -d "$POSTGRES_DATABASE" -U "$POSTGRES_USER" -c 'SELECT 1'
+        run_weblate shell -c 'from weblate.auth.models import User; User.objects.exists()'
         fail_dep PosgreSQL
     fi
     sleep 1
 done
 
-# Fetch server version
-PGVERSION=$(psql -h "$POSTGRES_HOST" -p "$POSTGRES_PORT" -d "$POSTGRES_DATABASE" -U "$POSTGRES_USER" -t -A -c 'SHOW server_version_num;')
+VERSION_CHECK=1
+case $WEBLATE_DATABASES in
+    0|[fF][aA][lL][sS][eE]|[nN][oO])
+        VERSION_CHECK=0
+        ;;
+esac
 
-unset PGPASSWORD
+if [ $VERSION_CHECK -eq 1 ] ; then
+    # Fetch server version
+    PGVERSION=$(psql -h "$POSTGRES_HOST" -p "$POSTGRES_PORT" -d "$POSTGRES_DATABASE" -U "$POSTGRES_USER" -t -A -c 'SHOW server_version_num;')
 
->&2 echo "Postgres $PGVERSION is up"
+    unset PGPASSWORD
 
-# Check if supported PostgreSQL version is used
-if [ "$PGVERSION" -lt 120000 ] ; then
-    >&2 echo "PostgreSQL 12 or newer is required to run Weblate"
-    >&2 echo "See https://docs.weblate.org/en/latest/admin/install/docker.html#upgrading-postgresql-container"
-    exit 1
+    >&2 echo "Postgres $PGVERSION is up"
+
+    # Check if supported PostgreSQL version is used
+    if [ "$PGVERSION" -lt 120000 ] ; then
+        >&2 echo "PostgreSQL 12 or newer is required to run Weblate"
+        >&2 echo "See https://docs.weblate.org/en/latest/admin/install/docker.html#upgrading-postgresql-container"
+        exit 1
+    fi
+else
+    >&2 echo "Database is up"
 fi
 
 # Migrate database to current version and collect static files