undo "client_body_in_file_only any"
and introduce "client_body_in_file_only clean"

introduce ngx_pool_delete_file() to not break a possible third-party
ngx_pool_cleanup_file() usage that may lead to an removal of the useful files

delete unnecessary ngx_http_finalize_request_body()
diff --git a/src/core/ngx_palloc.h b/src/core/ngx_palloc.h
index 2397281..76c6af1 100644
--- a/src/core/ngx_palloc.h
+++ b/src/core/ngx_palloc.h
@@ -60,7 +60,6 @@
 } ngx_pool_cleanup_file_t;
 
 
-
 void *ngx_alloc(size_t size, ngx_log_t *log);
 void *ngx_calloc(size_t size, ngx_log_t *log);
 
@@ -74,6 +73,7 @@
 
 ngx_pool_cleanup_t *ngx_pool_cleanup_add(ngx_pool_t *p, size_t size);
 void ngx_pool_cleanup_file(void *data);
+void ngx_pool_delete_file(void *data);
 
 
 #endif /* _NGX_PALLOC_H_INCLUDED_ */