fixup! added preferences commands in command handler

Author: andreagilardoni

main/CommandHandler.cpp

@@ -2144,7 +2144,11 @@ int pref_end(const uint8_t command[], uint8_t response[])
 
   preferences.end();
 
-  return 0;
+  response[2] = 1;          // number of parameters
+  response[3] = 1;          // length of first parameter
+  response[4] = 1;
+
+  return 6;
 }
 
 int pref_clear(const uint8_t command[], uint8_t response[])