remove extra newlines that eventlet seems to add

in the last month info lines in nova logs for wsgi requests are
getting extra new lines. This is suspected to be because eventlet
wsgi is adding those in, and using the WritableLogger. Do an rstrip
here to not have our logs full of blanks.

Change-Id: I130b08b1b4b5a48ecfa6418e7576d2bae2884f9e
Merge "remove extra newlines that eventlet seems to add"