Crash when importing TRANNNC for dual porosity model

Error reported by ert_abort_dump file:
Abort called from: assert_correct_kw_count (/private/jenkinstr/workspace/ResInsight-Master-RH6-Octave3.8.1-qt5-grpc-py3.6/ThirdParty/Ert/lib/ecl/ecl_nnc_data.cpp:172)

Error message: In function ecl_nnc_data_set_values, reading kw: TRANNNC. 258371 != 35

This model is a dual porosity model. The input data is checked and has consistent number NNC indexes and TRAN-values:
EGRID-file:
NNC1 258371:INTE
NNC2 258371:INTE

INIT-file:
TRANNNC 258371:REAL

## Callstack

## References
Issue reported in ResInsight https://github.com/OPM/ResInsight/issues/5690

## Dataset
@hhgs will provide dataset triggering this crash