Reorder comments to ensure clarity

Long history comment moved to the end with short clarifying comments
before the relevant code. Update changelog with proper attribution

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.687) UNRELEASED; urgency=medium
+
+  [ Stanislav German-Evtushenko <giner> ]
+  * Send Vagrant serial connection to NULL. (LP: #1874453)  
+
+ -- John Chittum <john.chittum@canonical.com>  Thu, 27 Aug 2020 14:48:36 -0500
+
 livecd-rootfs (2.686) groovy; urgency=medium
 
   [ Dan Streetman ]

live-build/ubuntu-cpc/hooks.d/base/vagrant.binary

@@ -154,15 +154,16 @@ Vagrant.configure("2") do |config|
 
   config.vm.provider "virtualbox" do |vb|
      vb.customize [ "modifyvm", :id, "--uart1", "0x3F8", "4" ]
-# Ubuntu cloud images, by default, enable tty=ss0. This enables serial consoles to
-# connect to the images. With the change related to LP #1777827, removing a serial
-# file logger, Vagrant image boot times increased and now run greater than 5 minutes
-# Creating a console log file is not an expected defaul behavior for vagrant boxes. LP #1777827
-# As a workaround, we create a console connection to File:NULL. LP #1874453
-# This is overwriteable in user files to write to a local file
-# Line below is an example of setting file local to the Vagrantfile
-#     vb.customize [ "modifyvm", :id, "--uartmode1", "file", File.join(Dir.pwd, "${prefix}-console.log") ]
+    # Create a NULL serial port to skip console logging by default
       vb.customize [ "modifyvm", :id, "--uartmode1", "file", File::NULL ]
+    # If console logging is desired, uncomment this line and remove prior
+    # vb.customize [ "modifyvm", :id, "--uartmode1", "file", File.join(Dir.pwd, "${prefix}-console.log") ]
+    # Ubuntu cloud images, by default, enable tty=ss0. This enables serial consoles to
+    # connect to the images. With the change related to LP #1777827, removing a serial
+    # file logger, Vagrant image boot times increased and now run greater than 5 minutes
+    # Creating a console log file is not an expected defaul behavior for vagrant boxes. LP #1777827
+    # As a workaround, we create a console connection to File:NULL. LP #1874453
+    # This is overwriteable in user files to write to a local file
   end
 end
 EOF