Monitor tserver page doesn't always load Dead Tablet Servers table

[jack-gitdev]

Describe the bug
The Dead Tablet Servers table on the Accumulo Monitor's tserver page does not consistently load, even though it has entries that can be displayed. Reloading using CTRL+F5 multiple times will eventually get it to load. Reloading can also cause the table to not load.

Versions (OS, Maven, Java, and others, as appropriate):

• Affected version(s) of this project: 2.1.4

To Reproduce
Steps to reproduce the behavior (or a link to an example repository that reproduces the problem):

1. Go to '{accumulo-monitor-url}/tservers'
2. Dead Tablet Servers table starts loading, then either loads fully or disappears.
3. Reload using CTRL+F5 to reattempt

Expected behavior
The Dead Tablet Servers table should load every time when there are entries to be displayed.