[PR #8693/7ca244ef backport][3.10] Fix missing logic in quickstart ex…

…ample (#8705)

**This is a backport of PR #8693 as merged into master
(7ca244e).**

Co-authored-by: NewUserHa <32261870+NewUserHa@users.noreply.github.com>

docs/web_quickstart.rst

@@ -441,8 +441,11 @@ third-party library, :mod:`aiohttp_session`, that adds *session* support::
 
     async def handler(request):
         session = await get_session(request)
-        last_visit = session['last_visit'] if 'last_visit' in session else None
-        text = 'Last visited: {}'.format(last_visit)
+
+        last_visit = session.get("last_visit")
+        session["last_visit"] = time.time()
+        text = "Last visited: {}".format(last_visit)
+
         return web.Response(text=text)
 
     async def make_app():