Not allow reset bu user input first 2 init sweep

Reset seep time if select < 2.5 ms

main.c

@@ -2729,12 +2729,12 @@ int main(void)
   redraw_frame();
   set_mode(M_HIGH);
   set_sweep_frequency(ST_STOP, (uint32_t) 30000000);
-  sweep(true);
+  sweep(false);
   osalThreadSleepMilliseconds(100);
 
   set_mode(M_LOW);
   set_sweep_frequency(ST_STOP, (uint32_t) 4000000);
-  sweep(true);
+  sweep(false);
   set_sweep_frequency(ST_STOP, (uint32_t) 350000000);
 
   set_refer_output(-1);

sa_core.c

@@ -1389,7 +1389,7 @@ pureRSSI_t perform(bool break_on_operation, int i, uint32_t f, int tracking)
     // manually set delay, for better sync
     if (setting.sweep_time_us < 2.5 * ONE_MS_TIME){
       setting.additional_step_delay_us = 0;
-      setting.sweep_time_us = setting.actual_sweep_time_us; // set minimum
+      setting.sweep_time_us = 0; // set minimum
     }
     else if (setting.sweep_time_us <= 3 * ONE_MS_TIME){
       setting.additional_step_delay_us = 1;