fix building --without-http-cache, broken in r2930

src/http/modules/ngx_http_proxy_module.c

diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index f0aadb4..f2d939e 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -2343,7 +2343,10 @@
     }
 
     if (conf->headers_set_hash.buckets
-        && ((conf->upstream.cache == NULL) == (prev->upstream.cache == NULL)))
+#if (NGX_HTTP_CACHE)
+        && ((conf->upstream.cache == NULL) == (prev->upstream.cache == NULL))
+#endif
+       )
     {
         return NGX_OK;
     }

src/http/ngx_http_upstream.c

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 87df571..19b6fb8 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -4086,7 +4086,10 @@
         conf->hide_headers_hash = prev->hide_headers_hash;
 
         if (conf->hide_headers_hash.buckets
-            && ((conf->cache == NULL) == (prev->cache == NULL)))
+#if (NGX_HTTP_CACHE)
+            && ((conf->cache == NULL) == (prev->cache == NULL))
+#endif
+           )
         {
             return NGX_OK;
         }