How to configure proxy in curl-loader?

    Syntax to be used:
  1. PROXY_AUTH_METHOD to be configured from the \"BASIC\", \"DIGEST\", \"GSS_NEGOTIATE\", \"NTLM\" or \"ANY\".
  2. PROXY_AUTH_CREDENTIALS to be provided in the form \"user:password\". If not configured, the loader uses USERNAME and PASSWORD tags value to synthesize the credentials.