doc: Add solution to live migration ssh issues
doc: Add solution to live migration ssh issues

This took me a good hour to suss and while there were a couple of Google
hits for it, the top suggestion was to use TCP (rather than SSH) and
disable all security, which is rarely good advice.

Paste an sample error and link to the doc where you can find advice of
resolving the issue.

Change-Id: I3805361834f7d954ae6759a22f61f02db139bcc5
Signed-off-by: Stephen Finucane <492121341a95b3c3aab646bed44634f739dd019b@redhat.com>

openstack/nova,openstack/nova,mahak/nova,openstack/nova,rahulunair/nova,klmitch/nova,klmitch/nova,rahulunair/nova,mahak/nova,klmitch/nova,klmitch/nova,rahulunair/nova,mahak/nova