--root should not be used to write the config file

[Matthias Klose]

seen in qmtest-2.4; the Debian build installs into a temporary
installation directory, which results in a wrong extension_path in the
config.py file.

  Matthias

--- qmtest-2.4.orig/qmdist/command/install_lib.py
+++ qmtest-2.4/qmdist/command/install_lib.py
@@ -49,7 +49,7 @@
         config_file = join(self.install_dir, 'qm', 'config.py')
         self.announce("adjusting config parameters")
         i = self.distribution.get_command_obj('install')
-        prefix = i.root or i.prefix
+        prefix = i.prefix
         extension_path = join('share',
                               'qmtest',
                               'site-extensions-%d.%d'%sys.version_info[:2])