Unload filament tweak

unload filament now has longer and faster slow retract.

Firmware/Marlin_main.cpp

@@ -5585,11 +5585,11 @@ case 404:  //M404 Enter the nominal filament width (3mm, 1.75mm ) N<3.0> or disp
 			//plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], 3500 / 60, active_extruder);
             
             target[E_AXIS] -= FILAMENTCHANGE_FINALRETRACT;
-            target[E_AXIS] -= 50;
+            target[E_AXIS] -= 45;
             plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], 5200 / 60, active_extruder);
             st_synchronize();
-            target[E_AXIS] -= 10;
-            plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], 80 / 60, active_extruder);
+            target[E_AXIS] -= 15;
+            plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], 160 / 60, active_extruder);
             st_synchronize();
             target[E_AXIS] -= 20;
             plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], 5000 / 60, active_extruder);
@@ -5985,11 +5985,11 @@ case 404:  //M404 Enter the nominal filament width (3mm, 1.75mm ) N<3.0> or disp
 
 //		extr_unload2();
 
-		current_position[E_AXIS] -= 50;
+		current_position[E_AXIS] -= 45;
 		plan_buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], 5200 / 60, active_extruder);
         st_synchronize();
-        current_position[E_AXIS] -= 10;
-        plan_buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], 80 / 60, active_extruder);
+        current_position[E_AXIS] -= 15;
+        plan_buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], 160 / 60, active_extruder);
         st_synchronize();
         current_position[E_AXIS] -= 20;
         plan_buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], 5000 / 60, active_extruder);