Remove unnecessary getattr() call

BaseDatabaseWrapper always has an alias attribute. [1]

[1] https://github.com/django/django/blob/aa28c392b9491f02330905cb73b7078b1cd18c60/django/db/backends/base/base.py#L70

Author: living180

debug_toolbar/panels/sql/tracking.py

@@ -156,7 +156,7 @@ def _record(self, method, sql, params):
                 pass  # object not JSON serializable
             template_info = get_template_info()
 
-            alias = getattr(self.db, "alias", "default")
+            alias = self.db.alias
             conn = self.db.connection
             vendor = getattr(conn, "vendor", "unknown")