fixed: do not dereference invalid iterator

[akva2]

if a well has connections added in an action, the well perf data is not yet initialized in the call to updateEclWells. it will however be reinitialized before the next time step so simply adding a bounds check here avoid the invalid dereference and the connection factor will take effect through the reinitialization.

ref e.g. https://ci.opm-project.org/job/opm-simulators-static-analysis/383/testReport/junit/(root)/debug_iterator/compareSeparateECLFiles_flow_pyaction_gruptree_insert_kw/

[akva2]

jenkins build this please

[bska]

On the face of it this looks benign, but I need to review the wider context here. Please hold any further action here.

[lisajulia]

You mean the perf data will be initialized here at the beginning of each time step (https://github.com/OPM/opm-simulators/blob/master/opm/simulators/wells/BlackoilWellModel_impl.hpp#L436 and then https://github.com/OPM/opm-simulators/blob/master/opm/simulators/wells/BlackoilWellModel_impl.hpp#L343) , right?

Looks fine :) @akva2: can you possibly add a comment about the newly introduced check and why it is needed?