ENH: set timeout for starting extrusion to 20

Change-Id: Iae718e324170028121ca32e9653acac7b7b301f4
Signed-off-by: Stone Li <stone.li@bambulab.com>

src/slic3r/GUI/DeviceManager.cpp

@@ -432,6 +432,7 @@ bool MachineObject::is_in_extrusion_cali()
     auto curr_time = std::chrono::system_clock::now();
     auto diff = std::chrono::duration_cast<std::chrono::milliseconds>(curr_time - last_extrusion_cali_start_time);
     if (diff.count() < EXTRUSION_OMIT_TIME) {
+        mc_print_percent = 0;
         return true;
     }