[ci optional] restore convective_bdy_weight to one place in the test suite

Author: evbauer

star/test_suite/diffusion_smoothness/inlist_diffusion_smoothness

@@ -64,6 +64,8 @@
       limit_for_rel_error_in_energy_conservation = 1d-6 ! this makes d2N2 too large.  takes 63 steps. log_rel_run_E_err  -3.5859393528096946
       limit_for_rel_error_in_energy_conservation = 1d-5 ! this is smooth enough.  takes 58 steps. log_rel_run_E_err  -3.4820705862368895
       hard_limit_for_rel_error_in_energy_conservation = 1d-4
+
+      convective_bdy_weight = 1
 
       cool_wind_RGB_scheme = 'Reimers'
       cool_wind_AGB_scheme = 'Blocker'