Disabled slipstreaming for low AI level.

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@6122 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/karts/kart.cpp

@@ -880,6 +880,9 @@ float Kart::handleNitro(float dt)
  */
 float Kart::handleSlipstream(float dt)
 {
+    // Low level AIs should not do any slipstreaming.
+    if(!getController()->isPlayerController() &&
+        race_manager->getDifficulty()==RaceManager::RD_EASY) return 0;
     // First see if we are currently using accumulated slipstream credits:
     // -------------------------------------------------------------------
     if(m_slipstream_mode==SS_USE)