drivers/hadgem3/CICE_RunMod: add call to 'save_init'

The hadgem3 driver was not updated when 'save_init' was added in 83686a3
(Implement box model test from 2001 JCP paper (CICE-Consortium#151), 2018-10-22). As
this subroutine is necessary to ensure proper initialization of the
model, add it now.

cicecore/drivers/direct/hadgem3/CICE_RunMod.F90

@@ -202,7 +202,7 @@ subroutine ice_step
          if (restore_ice) call ice_HaloRestore
 
       !-----------------------------------------------------------------
-      ! initialize diagnostics
+      ! initialize diagnostics and save initial state values
       !-----------------------------------------------------------------
 
          call ice_timer_start(timer_diags)  ! diagnostics/history
@@ -214,6 +214,8 @@ subroutine ice_step
          call ice_timer_start(timer_column)  ! column physics
          call ice_timer_start(timer_thermo)  ! thermodynamics
 
+         call save_init
+
          !$OMP PARALLEL DO PRIVATE(iblk)
          do iblk = 1, nblocks