Fix null value assignment for tag attributes in getAttributes method

Author: Matt3o12

src/PHPHtmlParser/Dom/Tag.php

@@ -326,13 +326,13 @@ public function makeOpeningTag()
         foreach (\array_keys($this->attr) as $key) {
             try {
                 $attributeDTO = $this->getAttribute($key);
+                $val = $attributeDTO->getValue();
             } catch (AttributeNotFoundException $e) {
                 // attribute that was in the array not found in the array... let's continue.
                 continue;
             } catch (\TypeError $e) {
-              $val = null;
+                $val = null;
             }
-            $val = $attributeDTO->getValue();
             if (\is_null($val)) {
                 $return .= ' ' . $key;
             } elseif ($attributeDTO->isDoubleQuote()) {