delete unneeded condition

src/http/ngx_http_file_cache.c

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 0cb81d9..efe0da6 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -356,10 +356,7 @@
         if (fcn->uses >= r->cache->min_uses) {
 
             r->cache->exists = fcn->exists;
-
-            if (fcn->body_start) {
-                r->cache->body_start = fcn->body_start;
-            }
+            r->cache->body_start = fcn->body_start;
 
             rc = NGX_OK;