Change the sign of comparing against density

Contributes to issue CURA-7287.

resources/quality/ultimaker_s5/um_s5_aa0.4_PLA_Draft_Print.inst.cfg

@@ -19,7 +19,7 @@ machine_nozzle_heat_up_speed = 1.6
 material_print_temperature = =default_material_print_temperature + 5
 material_standby_temperature = 100
 prime_tower_enable = False
-skin_edge_support_thickness = =0.8 if infill_sparse_density > 30 else 0
+skin_edge_support_thickness = =0.8 if infill_sparse_density < 30 else 0
 skin_overlap = 20
 speed_layer_0 = =math.ceil(speed_print * 20 / 70)
 speed_topbottom = =math.ceil(speed_print * 40 / 70)