title: Entering to my app hosted on firebase hosting redirects to google login page
body: <p>Was tweaking with Server Side Rendering and google cloud functions. Deployed everything on hosting and something really strange happens. When I enter my page, <a href="https://accounts.google.com" rel="noreferrer">https://accounts.google.com</a> page appears... </p>
  
  <p><a href="https://i.stack.imgur.com/M1eGH.png" rel="noreferrer"><img src="https://i.stack.imgur.com/M1eGH.png" alt="enter image description here"></a></p>
  
  <p>with some really long link:</p>
  
  <pre><code>https://accounts.google.com/signin/v2/identifier?
   service=ah&amp;passive=true&amp;continue=https%3A%2F%2Fappengine.google.com
    %2F_ah%2Fconflogin%3Fcontinue%3Dhttps%3A%2F%2Fus-central1-treebase-
     b21-d5.cloudfunctions.net%2Fssrapp%2F&amp;flowName=GlifWebSignIn&amp;flowEntry=
      ServiceLogin&amp;hl=en-GB
  </code></pre>
  
  <p>What may cause this? How to fix it? Thanks!</p>
  
  <h2><code>index.js</code> file responsible for SSR:</h2>
  
  <pre><code>import React from 'react';
  import { renderToString } from 'react-dom/server';
  import express from 'express';
  import App from './app/containers/App';
  import functions from 'firebase-functions';
  
  const app = express();
  
  app.get('**', (req, res) =&gt; {
    const html = renderToString(&lt;App /&gt;);
    res.set('Cache-Control', 'public, max-age=600, s-maxage=1200');
    res.send(`
      &lt;!doctype html&gt;
      &lt;html lang="en"&gt;
        &lt;head&gt;
          &lt;meta charset="utf-8"&gt;
          &lt;meta name="viewport" content="width=device-width, initial-scale=1"&gt;
        &lt;/head&gt;
  
        &lt;body&gt;
          &lt;div id="app"&gt;${html}&lt;/div&gt;
          &lt;div id="fb-root"&gt;&lt;/div&gt;
          &lt;script type="text/javascript" src="/main.30e39d69fe1ce70d8983.js"&gt;&lt;/script&gt;
        &lt;/body&gt;
      &lt;/html&gt;
    `);
  });
  
  export const ssrapp = functions.https.onRequest(app);
  </code></pre>
  
  <h2><code>firebase.json</code></h2>
  
  <pre><code>{
    "hosting": {
      "public": "build",
      "ignore": [
        "firebase.json",
        "**/.*",
        "**/node_modules/**"
      ],
      "rewrites": [
        {
          "source": "**",
          "function": "ssrapp"
        }
      ]
    }
  }
  </code></pre>