Merge pull request #497 from sosek108/master

Update installation.rst

Author: wouterj

book/installation.rst

@@ -135,7 +135,8 @@ And then access the CMF via:
     or set your database connection parameters in ``app/config/parameters.yml``.
     Make sure you leave the ``database_path`` property at ``null`` in order to
     use another driver than SQLite. Leaving the field blank in the
-    web-configurator will set it to ``null``.
+    web-configurator will set it to ``null``. 
+    You also need to uncomment lines in ``app/config/config.yml`` in section ``doctrine_dbal``.
 
 .. note::