Fix fnSetFilteringDelay when filtering disabled

Adds a check to fnSetFilteringDelay() that the table actually has the search box enabled - previously calling fnSetFilteringDelay() for a table without filtering would hijack ALL the search input box 'keyup' bindings on the whole page.

api/fnSetFilteringDelay.js

@@ -29,6 +29,8 @@ jQuery.fn.dataTableExt.oApi.fnSetFilteringDelay = function ( oSettings, iDelay )
 	}
 
 	this.each( function ( i ) {
+        	if ( typeof _that.fnSettings().aanFeatures.f !== 'undefined' )
+        	{
 			$.fn.dataTableExt.iApiIndex = i;
 			var
 				oTimerId = null,
@@ -48,6 +50,7 @@ jQuery.fn.dataTableExt.oApi.fnSetFilteringDelay = function ( oSettings, iDelay )
 			});
 	
 			return this;
+        	}
 	} );
 	return this;
 };