Removed unused prototype of ngx_http_find_server_conf().

This function prototype and its implementation was added in r90,
but the implementation was removed in r97.

src/http/ngx_http.h

diff --git a/src/http/ngx_http.h b/src/http/ngx_http.h
index bf70c16..c264f16 100644
--- a/src/http/ngx_http.h
+++ b/src/http/ngx_http.h
@@ -104,7 +104,6 @@
     ngx_http_chunked_t *ctx);
 
 
-ngx_int_t ngx_http_find_server_conf(ngx_http_request_t *r);
 void ngx_http_update_location_config(ngx_http_request_t *r);
 void ngx_http_handler(ngx_http_request_t *r);
 void ngx_http_run_posted_requests(ngx_connection_t *c);