Fix fpe in time smooth for ST

Time smoothing needs mstar_old but after a restart we have s% generations=0
so no _old values.

Author: rjfarmer

star/private/photo_in.f90

@@ -148,7 +148,7 @@ subroutine read_star_photo(s, fname, ierr)
             s% dq(1:nz), s% xa(:,1:nz), s% xh(:,1:nz), &
             s% omega(1:nz), s% j_rot(1:nz), s% mlt_vc(1:nz), s% conv_vel(1:nz), &
             s% D_ST_start(1:nz), s% nu_ST_start(1:nz), & ! needed for ST time smoothing
-            s% have_ST_start_info
+            s% have_ST_start_info, s% mstar_old ! needed for ST time smoothing
 
          call read_part_number(iounit)
          if (failed('rsp_num_periods')) return

star/private/photo_out.f90

@@ -85,7 +85,7 @@ subroutine output_star_photo(s,iounit,ierr)
             s% dq(1:nz), s% xa(:,1:nz), s% xh(:,1:nz), &
             s% omega(1:nz), s% j_rot(1:nz), s% mlt_vc(1:nz), s% conv_vel(1:nz), &
             s% D_ST_start(1:nz), s% nu_ST_start(1:nz), & ! needed for ST time smoothing
-            s% have_ST_start_info
+            s% have_ST_start_info, s% mstar_old ! needed for ST time smoothing
 
          call write_part_number(iounit)
          write(iounit) &

star_data/public/star_data_def.inc

@@ -1,7 +1,7 @@
 
       character(len=24) :: version_number ! mesa version from file $MESA_DIR/data/version_number
 
-      integer, parameter :: star_def_version = 17
+      integer, parameter :: star_def_version = 18
 
       integer, parameter :: nz_alloc_extra = 200