Fix reST label for collections ABCs.
The previous markup hijacked the abstract-base-classes glossary entry,
which resulted in the HTML linking to collections.abc when defining the
generic ABC concept. Now the glossary links to the abc module.
diff --git a/Doc/library/collections.abc.rst b/Doc/library/collections.abc.rst
index 58354f8..1d451d1 100644
--- a/Doc/library/collections.abc.rst
+++ b/Doc/library/collections.abc.rst
@@ -23,7 +23,7 @@
.. versionchanged:: 3.3
Formerly, this module was part of the :mod:`collections` module.
-.. _abstract-base-classes:
+.. _collections-abstract-base-classes:
Collections Abstract Base Classes
---------------------------------