ssi did work with memcached and nonbuffered responses

src/http/modules/ngx_http_ssi_filter_module.c

diff --git a/src/http/modules/ngx_http_ssi_filter_module.c b/src/http/modules/ngx_http_ssi_filter_module.c
index 5045fd6..8faf14c 100644
--- a/src/http/modules/ngx_http_ssi_filter_module.c
+++ b/src/http/modules/ngx_http_ssi_filter_module.c
@@ -843,7 +843,7 @@
             continue;
         }
 
-        if (ctx->buf->last_buf || ctx->buf->recycled) {
+        if (ctx->buf->last_buf || ngx_buf_in_memory(ctx->buf)) {
             if (b == NULL) {
                 if (ctx->free) {
                     cl = ctx->free;