fix pep-8 in export_all_courses

cms/djangoapps/contentstore/management/commands/export_all_courses.py

@@ -39,11 +39,9 @@ class Command(BaseCommand):
             if 1:
                 try:
                     location = CourseDescriptor.id_to_location(course_id)
-                    course_dir = course_id.replace('/','...')
+                    course_dir = course_id.replace('/', '...')
                     export_to_xml(ms, cs, location, root_dir, course_dir, modulestore())
                 except Exception as err:
                     print "="*30 + "> Oops, failed to export %s" % course_id
                     print "Error:"
                     print err
-                    
-