In kilo, the manila functionality for limiting request body size was
was moved to oslo.middleware library [1] and compatibility shims and
deprecation log messages were added for the manila
RequestBodySizeLimiter, whose function had been superceded by the
equivalent oslo library object.
It has now been more than two releases since the deprecation so
this commit removes the compatibility shims and log messages.
[1] I10c3cbeb9d43b504f14375df4dac87b323fab5bf
Change-Id: I01cc6585c15af9b13b178e26d4b469825dbd562c
e03d3d2ebe