Close the client postgresql connection after rejection. (#4084)

Co-authored-by: Manuel Vázquez Acosta <manuel@merchise.org>

server/util-server.js

@@ -458,6 +458,7 @@ exports.postgresQuery = function (connectionString, query) {
                     });
                 } catch (e) {
                     reject(e);
+                    client.end();
                 }
             }
         });