Add support for #4 - Make Postgres port configurable at run time

start.sh

@@ -8,6 +8,8 @@ if [[ ! -f ledgersmb.conf ]]; then
   sed -i \
     -e "s/\(cache_templates = \).*\$/cache_templates = 1/g" \
     -e "s/\(host = \).*\$/\1$POSTGRES_HOST/g" \
+    -e "s/\(port = \).*\$/\1$POSTGRES_PORT/g" \
+    -e "s/\(default_db = \).*\$/\1$DEFAULT_DB/g" \
     -e "s%\(sendmail   = \).*%\1/usr/bin/ssmtp%g" \
     /srv/ledgersmb/ledgersmb.conf
 fi