fixed MysqlAdapter check in Utf8mb4Fix migration

Author: GustavoPeixoto

config/Migrations/20171013133145_Utf8mb4Fix.php

@@ -1,6 +1,8 @@
 <?php
 
 use Cake\Error\Debugger;
+use Phinx\Db\Adapter\AdapterInterface;
+use Phinx\Db\Adapter\AdapterWrapper;
 use Phinx\Db\Adapter\MysqlAdapter;
 use Phinx\Migration\AbstractMigration;
 
@@ -16,7 +18,7 @@ class Utf8mb4Fix extends AbstractMigration {
 	 *
 	 * @return void
 	 */
-	public function change() {
+	public function change(): void {
 		$table = $this->table('queue_processes');
 		$table->changeColumn('pid', 'string', [
 			'length' => 40,
@@ -64,9 +66,8 @@ public function change() {
 			'collation' => 'utf8mb4_unicode_ci',
 		]);
 		$table->update();
-
 		//TODO: check adapter and skip for postgres, instead of try/catch
-		if ($this->adapter instanceof MysqlAdapter) {
+		if ($this->getUnwrappedAdapter() instanceof MysqlAdapter) {
 			try {
 				$table = $this->table('queued_jobs');
 				$table->changeColumn('data', 'text', [
@@ -90,4 +91,19 @@ public function change() {
 		}
 	}
 
+	/**
+	 * Gets the unwrapped adapter
+	 *
+	 * @return \Phinx\Db\Adapter\AdapterInterface|null
+	 */
+	private function getUnwrappedAdapter(): ?AdapterInterface {
+		$adapter = $this->adapter;
+
+		while ($adapter instanceof AdapterWrapper) {
+			$adapter = $adapter->getAdapter();
+		}
+
+		return $adapter;
+	}
+
 }