RestApiServlet: Flush pending padding as well

This issue was found by scan.coverity.com (CID 19911)
which is a static code analysis tool, free for open source
code. Originally it was classified as a resource leak, but
this is a miss classification as the auto closing of the
OutputStream will flush any pending padding.

Change-Id: I4dc2d1cd9f52740490fda7c37e98b115fa59ec3a
1 file changed