Bug when using single cut with update_displacement_field = 1

When running a computation with the single cut and with the option update_displacement_field = 1 (use of previous displacement field at the begining of a Newton Raphson loop), the computation may abort in the xtls::TLSEnrichment_3::updateValues.

A "quick" fix is to use update_displacement_field = 0, in order not to use the updateValues function. Note that this problem has not been observed with the double cut (tested on the Lshaped test case, with 8 different computations for the single cut and 8 different computations for the double cut).