yiic migrate/create should not require db component

framework/yii/console/controllers/MigrateController.php

@@ -115,11 +115,13 @@ class MigrateController extends Controller
 			}
 			$this->migrationPath = $path;
 
-			if (is_string($this->db)) {
-				$this->db = Yii::$app->getComponent($this->db);
-			}
-			if (!$this->db instanceof Connection) {
-				throw new Exception("The 'db' option must refer to the application component ID of a DB connection.");
+			if($action->id!=='create') {
+				if (is_string($this->db)) {
+					$this->db = Yii::$app->getComponent($this->db);
+				}
+				if (!$this->db instanceof Connection) {
+					throw new Exception("The 'db' option must refer to the application component ID of a DB connection.");
+				}
 			}
 
 			$version = Yii::getVersion();