ditch Libre, undo install.rst to prevent merge conflicts in https://github.com/opnsense/docs/pull/456

source/manual/install.rst

@@ -217,6 +217,17 @@ Media Filename Composition
   repository, see `README <https://pkg.opnsense.org/releases/mirror/README>`__
 
 
+--------------------
+OpenSSL and LibreSSL
+--------------------
+
+OPNsense images are provided based upon `OpenSSL <https://www.openssl.org>`__.
+The `LibreSSL <http://www.libressl.org>`__ flavor can be selected from within
+the GUI (:menuselection:`System --> Firmware --> Settings`). In order to apply your choice an update
+must be performed after save, which can include a reboot of the system.
+
+.. image:: ./images/firmware_flavour.png
+
 
 -------------------------
 Boot preparation