fix seg fault

Author: okBrian

src/simulation/m_start_up.fpp

@@ -212,7 +212,7 @@ contains
             if (cfl_adap_dt .or. cfl_const_dt .or. rkck_adap_dt) cfl_dt = .true.
 
             if (any((/bc_x%beg, bc_x%end, bc_y%beg, bc_y%end, bc_z%beg, bc_z%end/) == -17) .or. &
-                num_bc_patches /= dflt_int) then
+                num_bc_patches > 0) then
                 read_bc = .true.
             endif