Pin umi to version 3.1.1 (#6359)

Co-authored-by: Ndepfu[bot] <23717796+depfu[bot]@users.noreply.github.com>

package.json

@@ -71,7 +71,7 @@
     "react": "^16.8.6",
     "react-dom": "^16.8.6",
     "react-helmet-async": "^1.0.4",
-    "umi": "^3.1.0",
+    "umi": "3.1.1",
     "umi-request": "^1.0.8",
     "use-merge-value": "^1.0.1"
   },