Bug #46899 Slow Query Log Not Enabled rule missing value tag in thresholdList

Description:
The "Slow Query Log Not Enabled" rule is missing a <value> tag in the <thresholdList>.  This is causing a stack trace for some people when the Service Manager is started.

How to repeat:
1) Start the Service Manager
2) Look for stack trace in the tomcat console

Andy Bang writes: 
Pushed up to revision 304.

Keith Russell writes: 
Patch installed in versions => 2.1.0.1096.

Eric Herman writes: 
the stack-trace was an ArrayIndexOutOfBoundsException and can be seen at the following secure-pastebin:

https://intranet.mysql.com/secure/paste/displaypaste.php?codeid=8717

With the change from "category" to "tags", our sanity-check code was not previously allowing for the possiblilty that a "bad" rule could mean a rule not only with no tag[0] being an empty string, but potentially with no tags defined at all.

A test and a fix has been pushed to trunk for this situation, which results in a slightly more clear exception here:

https://intranet.mysql.com/secure/paste/displaypaste.php?codeid=8754

The root cause seems to be a 2.2 server getting a 2.1 advisors.

An entry was added to the 2.1.0 changelog:

The “Slow Query Log Not Enabled” rule was missing a <value> tag in the <thresholdList> block. This caused a stack trace to be generated when the Service Manager started.