Fixed an issue with no value attributes

Author: paquettg

src/PHPHtmlParser/Dom/Tag.php

@@ -98,11 +98,14 @@ public function noise($noise)
 	 */
 	public function setAttribute($key, $value)
 	{
-		// convert charset
-		$encode = new Encode;
-		$encode->from(Dom::$expectedCharset);
-		$encode->to(Dom::$charset);
-		$value['value'] = $encode->convert($value['value']);
+		if (is_string($value['value']))
+		{
+			// convert charset
+			$encode = new Encode;
+			$encode->from(Dom::$expectedCharset);
+			$encode->to(Dom::$charset);
+			$value['value'] = $encode->convert($value['value']);
+		}
 
 		$this->attr[$key] = $value;
 		return $this;