fixed endless loop when blockquote had not empty line after

src/Parser.php

@@ -468,7 +468,7 @@ class Parser {
 		}
 		$buffer = "";
 		$elm    = $this->document->createElement("blockquote", $buffer);
-		while (!($this->current()->type === TokenType::EOL && $this->next()->type !== TokenType::GT)) {
+		while (!($this->current()->type === TokenType::EOF) && !($this->current()->type === TokenType::EOL && $this->next()->type !== TokenType::GT)) {
 			$gt   = $this->consume();
 			if ($this->current()->type === TokenType::EOL) {
 				$this->consume();