[ci skip] Partial patch for #2284

The issue description is about update_string(), which
I'm not sure if can be fixed at all. This patch only
addresses protect_identifiers().
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 7d8ef83..4988157 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -7,6 +7,10 @@
 
 Release Date: Not Released
 
+Bug fixes for 3.0.2
+-------------------
+
+-  Fixed a bug (#2284) - :doc:`Database <database/index>` method ``protect_identifiers()`` breaks when :doc:`Query Builder <database/query_builder>` isn't enabled.
 
 Version 3.0.1
 =============