Added Global Setting to Server config tab to
  - Enable & Disable the feature
  - Set the Proxy HTTP & HTTPS Ports

Added Per site level switch to enable and disable feature (Located in the Web Tab under the advanced section)

Added Apache2 and Nginx vhost updates to enable proxy_protocol on the listen lines

Added New database column to web_domain called "proxy_protocol" to enable site level config (Patch file Added upd_0089.sql)

Updated the Base Table SQL file to include "proxy_protocol" field

Fixed#5019 LE cert problem in mirror setups. This patch disables the creation of Let's encrypt SSL certs on mirrored slave servers.

Fixed #4667 Websites UI / Let's Encrypt :: add Option to allow switching to fullchain.pem in favor of chain.pem

- typo