Update simplepie.inc.php

interface/lib/classes/simplepie.inc.php

@@ -13338,7 +13338,7 @@ class SimplePie_Parse_Date
 			}
 
 			// Convert the number of seconds to an integer, taking decimals into account
-			$second = round($match[6] + $match[7] / pow(10, strlen($match[7])));
+			$second = round($match[6] + $match[7] / pow(10, (int)strlen($match[7])));
 
 			return gmmktime($match[4], $match[5], $second, $match[2], $match[3], $match[1]) - $timezone;
 		}