mod_ratelimit: Don't interfere with "chunked" encoding.

By the time ap_http_header_filter() sends the header brigade and adds the
"CHUNK" filter, we need to garantee that the header went through all the
filters' stack, and more specifically above ap_http_chunk_filter() which
assumes that all it receives is content data.

Since rate_limit_filter() may retain the header brigade, make it run after
ap_http_chunk_filter(), just before AP_FTYPE_CONNECTION filters.

This fixes the regression introduced in 2.4.34 (r1835168).
PR 62568.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1837130 13f79535-47bb-0310-9956-ffa450edef68