Revert "Continue reporting on URL format KeyError"

This reverts commit 25d4c4f79ef5883694b47290dfbee574f1f71829.

In fact it's better for Zuul to just throw an exception into its log
and not report on the change at all if it can't figure out how to
format the report string/build parameters.

Change-Id: Id0da8cd6a3bd35000b6e41c453947f25bbd08459
Merge "Revert "Continue reporting on URL format KeyError""