adding API_HOST and API_PORT to be read from environment or default a…

[rajendrakumaryadav]

Added API_HOST and API_PORT for reading the configration from environment, fallback option will be "http://localhost" port will be 3000.

Snippet:

'use strict';

module.exports = {
  tileLayer: 'http://{s}.tile.osm.org/{z}/{x}/{y}.png',
  host: process.env.API_HOST || 'http://localhost', # Updated this line
  port: process.env.API_PORT || '3000',             # Updated this line
  maxTaskNumber: 100,
  overpassEndpoint: 'https://overpass-api.de/api/interpreter'
};