Fix TypeError

This closes select2#3160.

Author: kevin-brown

dist/js/select2.full.js

@@ -5832,7 +5832,7 @@ S2.define('jquery.select2',[
   // Hold the AMD module references on the jQuery function that was just loaded
   // This allows Select2 to use the internal loader outside of this file, such
   // as in the language files.
-  $.fn.select2.amd = S2;
+  jQuery.fn.select2.amd = S2;
 
   // Return the Select2 instance for anyone who is importing it.
   return select2;

dist/js/select2.full.min.js

@@ -5272,7 +5272,7 @@ S2.define('jquery.select2',[
   // Hold the AMD module references on the jQuery function that was just loaded
   // This allows Select2 to use the internal loader outside of this file, such
   // as in the language files.
-  $.fn.select2.amd = S2;
+  jQuery.fn.select2.amd = S2;
 
   // Return the Select2 instance for anyone who is importing it.
   return select2;

dist/js/select2.js

@@ -5,7 +5,7 @@
   // Hold the AMD module references on the jQuery function that was just loaded
   // This allows Select2 to use the internal loader outside of this file, such
   // as in the language files.
-  $.fn.select2.amd = S2;
+  jQuery.fn.select2.amd = S2;
 
   // Return the Select2 instance for anyone who is importing it.
   return select2;