Python: Update strange-essaflow test

Author: tausbn

python/ql/test/experimental/dataflow/strange-essaflow/testFlow.expected

@@ -2,10 +2,4 @@ os_import
 | test.py:2:8:2:9 | GSSA Variable os |
 flowstep
 jumpStep
-| test.py:2:8:2:9 | GSSA Variable os | test.py:5:7:5:21 | ControlFlowNode for Flask() |
-| test.py:2:8:2:9 | GSSA Variable os | test.py:7:2:7:23 | ControlFlowNode for Attribute() |
-| test.py:2:8:2:9 | GSSA Variable os | test.py:7:2:7:23 | ControlFlowNode for Attribute()() |
 essaFlowStep
-| test.py:2:8:2:9 | GSSA Variable os | test.py:5:7:5:21 | ControlFlowNode for Flask() |
-| test.py:2:8:2:9 | GSSA Variable os | test.py:7:2:7:23 | ControlFlowNode for Attribute() |
-| test.py:2:8:2:9 | GSSA Variable os | test.py:7:2:7:23 | ControlFlowNode for Attribute()() |