Proxy: error checking for array init, missed in 7716:d6a5e14aa3e4.

Found by Coverity (CID 1467637).
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 17e4761..c5c9e85 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -2679,7 +2679,9 @@
     ngx_keyval_t               *attr;
     ngx_http_proxy_loc_conf_t  *plcf;
 
-    ngx_array_init(&attrs, r->pool, 2, sizeof(ngx_keyval_t));
+    if (ngx_array_init(&attrs, r->pool, 2, sizeof(ngx_keyval_t)) != NGX_OK) {
+        return NGX_ERROR;
+    }
 
     if (ngx_http_proxy_parse_cookie(&h->value, &attrs) != NGX_OK) {
         return NGX_ERROR;