Prevent external router IPs from being sent back

In anticipation of change Iba7c606eea48181fc10e9d0d5dc667e6f48f37de
being merged or at least a minimum a fix for bug #1255142, the
router response will have external IP address information available
that is not mutable by a regular tenant. This patch removes that
information from the response before replaying it back for a router
update.

Change-Id: Id1da9246bca2a2eee69f751856ffa7052eb18ef9
Increase default maximum safe_body function

There is this specific test test_absolute_limits_negative which's xml
version is bigger than 2048 characters and was truncated on tempest.log
that is fixed increasing that maximum even though I'm not sure how long
xml tests will live here.
Closes-Bug: #1383996

Change-Id: I771921e3c14333afc791e21395c0edf9feba5ee0
Merge "Prevent external router IPs from being sent back"
Merge "Increase default maximum safe_body function"