Fix "Attempt to read property "length" on array" error

Author: lfglopes

src/PhpWord/Shared/XMLReader.php

@@ -62,7 +62,7 @@ public function getDomFromZip($zipFile, $xmlFile)
 
         $zip = new ZipArchive();
         $zip->open($zipFile);
-        $content = $zip->getFromName($xmlFile);
+        $content = $zip->getFromName(ltrim($xmlFile, '/'));
         $zip->close();
 
         if ($content === false) {