CC-4677: Improve Smart block repeat description

-fixed

airtime_mvc/public/js/airtime/playlist/smart_blockbuilder.js

@@ -402,8 +402,9 @@ function setupUI() {
     
     $(".repeat_tracks_help_icon").qtip({
         content: {
-            text: "If your criteria is too strict, Airtime may not be able to fill up the desired smart block length." +
+            text: "The desired block length will not be reached if Airtime cannot find " +
-                  " Hence, if you check this option, tracks will be used more than once."
+            "enough unique tracks to match your criteria. Enable this option if you wish to allow " +
+            "tracks to be added multiple times to the smart block."
         },
         hide: {
             delay: 500,