Web page is confused when I shutdown the only slave

[GuoTengda1993]

Describe the bug

I started locust as master-slave mode (just 1 slave). When locust is running, I shutdown the slave.
When I refresh the web page, it become confused, refresh is useless.

In console, master already set the slave missing

Expected behavior

Web page is OK

Actual behavior

See the image above

Steps to reproduce

1. run locust master;
2. run 1 slave;
3. shutdown slave;
4. press "Stop" button
5. refresh the web page

Environment

• OS: win 7 x64
• Python version: 3.7.0
• Locust version: 0.14.4
• Locust command line that you ran: locust -f boomer_master.py --master
• Locust file contents (anonymized if necessary): Golang scripts (drived by boomer), I think it doesn't matter with this bug.

[heyman]

I can reproduce this bug using the steps described.