test degradation parameters

src/http/modules/ngx_http_degradation_module.c

diff --git a/src/http/modules/ngx_http_degradation_module.c b/src/http/modules/ngx_http_degradation_module.c
index 53fde21..b221f22 100644
--- a/src/http/modules/ngx_http_degradation_module.c
+++ b/src/http/modules/ngx_http_degradation_module.c
@@ -198,9 +198,14 @@
                                "invalid sbrk size \"%V\"", &value[1]);
             return NGX_CONF_ERROR;
         }
+
+        return NGX_CONF_OK;
     }
 
-    return NGX_CONF_OK;
+    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                       "invalid parameter \"%V\"", &value[1]);
+
+    return NGX_CONF_ERROR;
 }