remove unused isPrintingPDFFragments function

js/reveal.js

@@ -1829,15 +1829,6 @@
 
 	}
 
-	/**
-	 * Check if this instance is being used to print a PDF with fragments.
-	 */
-	function isPrintingPDFFragments() {
-
-		return ( /print-pdf-fragments/gi ).test( window.location.search );
-
-	}
-
 	/**
 	 * Hides the address bar if we're on a mobile device.
 	 */