docs: fix label position

Author: kenjis

user_guide_src/source/dbmgmt/forge.rst

@@ -288,6 +288,8 @@ You may add keys to an existing table by using ``processIndexes()``:
 
 .. literalinclude:: forge/029.php
 
+.. _dropping-a-primary-key:
+
 Dropping a Primary Key
 ======================
 
@@ -304,8 +306,6 @@ Execute a DROP KEY.
 
 .. literalinclude:: forge/020.php
 
-.. _dropping-a-primary-key:
-
 Dropping a Foreign Key
 ======================