Do not try to load geometry on start
This is partial revert of !413 (merged).
At the time, to initialize the geometry in multithreaded jobs, sine BeginEvent could not be used, we had to hook onto the start
transition.
Since then we introduced a new mechanism to ensure that the conditions are properly loaded (!1732 (merged)), so we do not need anymore to use UpdateManagerSvc::start
... which is actually harmful for cases like Rec!2860 (merged).