fix commit refs

Author: hjwp

chapter_post_and_database.asciidoc

@@ -849,7 +849,7 @@ creating a class:
 
 [[first-django-model]]
 [role="sourcecode"]
-.lists/models.py  (ch05l019)
+.lists/models.py (ch05l019)
 ====
 [source,python]
 ----
@@ -876,7 +876,7 @@ model, we make it inherit from the `Model` class:
 
 
 [role="sourcecode"]
-.lists/models.py  (ch05l020)
+.lists/models.py (ch05l020)
 ====
 [source,python]
 ----