Add link to management security domain to security guide

Migration network section needs link to management security domain (just in
case reference is needed), and then changing indeed to with as it's currently not a comprehensible sentence.

Change-Id: Iab1468bb15f823e4695e32b1b06a7e65d402ad85
Closes-Bug: #1344361
Merge "Add link to management security domain to security guide"