[mod_webdav] webdav_reqbody_type_xml() fixes
[mod_webdav] webdav_reqbody_type_xml() fixes

webdav_reqbody_type_xml() must check request headers (behavior fix)
protect webdav_reqbody_type_xml() with USE_PROPPATCH (compile fix)

gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4