Cache size accounting fix: actual cache size on disk was less than

needed by sum of sizes of files loaded by worker processes themselves
while cache loader was running.

The bug has been introduced in r3900.

src/http/ngx_http_file_cache.c

@@ -408,6 +408,7 @@ ngx_http_file_cache_read(ngx_http_request_t *r, ngx_http_cache_t *c)
             c->node->body_start = c->body_start;
             c->node->exists = 1;
             c->node->uniq = c->uniq;
+            c->node->fs_size = c->fs_size;
 
             cache->sh->size += c->fs_size;
         }