openssh: disable passwotdh auth if set in os.openelec.settings

packages/network/openssh/init.d/51_sshd

@@ -81,10 +81,16 @@
         cp /etc/ssh/known_hosts $HOME/.ssh
       fi
 
+    # Check if password authentication is disabled
+      OPTIONS=""
+
+      if [ "$SSHD_DISABLE_PW_AUTH" == "true" ] ; then
+        OPTIONS="-o 'PasswordAuthentication no'"
+      fi
       progress "Starting SSH Server"
 
       mkdir -p /var/empty
       chmod -R 600 /var/empty
-      $SSHD
+      eval $SSHD $OPTIONS
     fi
   )&