Deployment bugfixes

[andreishket]

Changes:

• Added python3-dev dependency in the Dockerfile in the server/workers/base;
• Updated the Dockerfile in the Headstart;
• Updated the hotreload script: added a script that checks that the config.js presented;
• Updated the hotreload script: added a script that checks that the .htaccess file presented in the project-website, if not it will create one from the settings.htaccess file.