Misleading lang string

[matthewhilton]

Some of the lang string I believe were messed up, for e.g.

https://github.com/catalyst/moodle-tool_heartbeat/blob/789b1ef0b8c8a8ea1e34f637c80e28f2ac6ca0cd/classes/check/tasklatencycheck.php#L115-L122

Code is checking if the lastruntime < $completiondelay, but the lang string outputs:

$string['latencynotrun'] = 'Task {$a->task} has not run within the configured latency threshold: {$a->mins}.';

But it should most likely be using this:

$string['latencyruntime'] = 'Task {$a->task} was last run with a runtime longer than the configured threshold: {$a->mins}.';