corrected: avoid shadowing of variable

--- a/Admin/mira.py	Tue Jul 03 13:56:12 2012 +0200
+++ b/Admin/mira.py	Tue Jul 03 21:51:16 2012 +0200
@@ -32,10 +32,10 @@
         raise IOError('Bad file: %s' % loc_contrib)
     subprocess.check_call(['ln', '-s', loc_contrib, '%s/contrib' % loc_isabelle])
 
-    components = path.join(loc_isabelle, 'Admin', 'components')
-    if path.exists(components):
+    components_registry = path.join(loc_isabelle, 'Admin', 'components')
+    if path.exists(components_registry):
         components = []
-        for component in util.readfile_lines(components):
+        for component in util.readfile_lines(components_registry):
             loc_component = path.join(loc_isabelle, component)
             if path.exists(loc_component):
                 components.append(loc_component)