mod_rewrite: fix a problem in the proxy support of mod_rewrite. The broken
code was inserting multiple "proxy:" fields in the rewritten URIs.
[Submitted by:  Eider Oliveira <eider@bol.com.br>]
[Updated and reviewed by: Paul J. Reder]


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@100600 13f79535-47bb-0310-9956-ffa450edef68