The content-length filter needs to compute the length even if the

content-length has already been set.  If we don't, then we won't know if
the content-length has changed because some other filter changed the
length of the actual data.  We also ALWAYS want to calculate the content
length if we get the whole brigade in the first call to this function.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86879 13f79535-47bb-0310-9956-ffa450edef68