Fixed a slow id generator rebuild high id issue

where the high id would be set too high.
Also removes a test that, using complicated breakpoint testing, basically
tested that IdGeneratorImpl#setHighId throws exception when given -1 as
high Id. Replaced with a unit test.
Merge pull request #3142 from tinwelint/2.2-too-high-id-after-slow-rebuild

[2.2] Fixed a slow id generator rebuild high id issue