Error while retrieving data from Test Runs report if the instance contains invalid Test Runs

If the Jira instance contains invalid Test Runs, the system may throw a NullPointerException and the error 500 is returned to the Browser.

Xray should catch the NullPointerException and log an error informing that an invalid Test Run was being loaded.

A workaround for this problem is to fix the invalid Test Runs by running the Xray integrity checker.