Remove more calls update_rbw

Not need made dirty in it

sa_cmd.c

@@ -552,7 +552,7 @@ VNA_SHELL_FUNCTION(cmd_scanraw)
   int old_step = setting.frequency_step;
   float f_step = (stop-start)/ points;
   setting.frequency_step = (int32_t)f_step;
-  update_rbw();
+
   streamPut(shell_stream, '{');
   static  uint32_t old_start=0, old_stop=0, old_points=0;
   if (old_start != start || old_stop != stop || old_points != points) {

sa_core.c

@@ -1084,7 +1084,6 @@ void update_rbw(void)           // calculate the actual_rbw and the vbwSteps (#
     setting.vbw_x10 = actual_rbw_x10;
     vbwSteps = 1;               // only one vbwSteps
   }
-  dirty = true;
 }
 
 int binary_search_frequency(int f)      // Search which index in the frequency tabled matches with frequency  f using actual_rbw