Add neuler test before reading restart in dynspg_ts

[mathiot]

Context

With ln_bt_fw, dynspg_ts needs ub2_b, vb2_b, un_bf, vn_bf, sshbb_e, ubb_e, vbb_e, sshb_e, ub_e, vb_e to start. If we start from an Euler time step (or a reduce restart), reading these variables is not needed (overwrite later on).
A test on neuler was present in 3.6_STABLE to avoid reading these variables when started on an euler time step. The test was removed between 3.6_STABLE and 4.0_beta .

Recommendation

Add a test on neuler in ts_rst to avoid reading variables mentioned earlier.

It means replace:

   SUBROUTINE ts_rst( kt, cdrw )
 ...
         IF( ln_rstart .AND. ln_bt_fw) THEN    !* Read the restart file
            CALL iom_get( numror, jpdom_autoglo, 'ub2_b'  , ub2_b  (:,:), ldxios = lrxios )
            ...

by

   SUBROUTINE ts_rst( kt, cdrw )
 ...
         IF( ln_rstart .AND. ln_bt_fw .AND. (neuler/=0) ) THEN    !* Read the restart file
            CALL iom_get( numror, jpdom_autoglo, 'ub2_b'  , ub2_b  (:,:), ldxios = lrxios )
            ...

Tests with AMM12 show no change in results.

[mathiot]

In 10256:

Error: Failed to load processor CommitTicketReference

No macro or processor named 'CommitTicketReference' found