Python: update test expectations

Author: yoff

python/ql/test/experimental/dataflow/tainttracking/customSanitizer/TestTaint.expected

@@ -1,5 +1,5 @@
 test_taint
-| test.py:22 | fail | test_custom_sanitizer | s |
+| test.py:22 | ok   | test_custom_sanitizer | s |
 | test.py:36 | fail | test_custom_sanitizer_guard | s |
 | test.py:38 | ok   | test_custom_sanitizer_guard | s |
 | test.py:49 | ok   | test_escape | s2 |