fix typo

Author: rouilj

test/test_liveserver.py

@@ -8,7 +8,7 @@
 from .wsgi_liveserver import LiveServerTestCase
 from . import db_test_base
 from time import sleep
-from .test_postresql import skip_postgresql
+from .test_postgresql import skip_postgresql
 
 from wsgiref.validate import validator