Fix: Catastrophic Backtracking RegExp

Author: juzser

src/PhpWord/TemplateProcessor.php

@@ -737,7 +737,7 @@ public function cloneBlock($blockname, $clones = 1, $replace = true, $indexVaria
         $xmlBlock = null;
         $matches = array();
         preg_match(
-            '/(.*((?s)<w:p\b(?:(?!<w:p\b).)*?\${' . $blockname . '}<\/w:.*?p>))(.*)((?s)<w:p\b(?:(?!<w:p\b).)*?\${\/' . $blockname . '}<\/w:.*?p>)/is',
+            '/(.*((?s)<w:p\b(?:(?!<w:p\b).)*?\${' . $blockname . '}<\/w:.*?p>))(.*)((?s)<w:p\b(?:(?!<w:p\b).)[^$]*?\${\/' . $blockname . '}<\/w:.*?p>)/is',
             $this->tempDocumentMainPart,
             $matches
         );