Fix inconsistent indentation

tests/test_nilmrun.py

@@ -309,7 +309,7 @@ class TestClient(object):
         sys.exit(0)  # also test raising SystemExit
         """)
         with assert_raises(ClientError) as e:
-	    do(code, ["hello", 123], False)
+            do(code, ["hello", 123], False)
         in_("400 Bad Request", str(e.exception))
         status = do(code, ["hello", "123"], False)
         eq_(status["log"], "hello 123\n")