Update readme.python.md (#17260)

Author: msyyc

specification/streamanalytics/resource-manager/readme.python.md

@@ -2,10 +2,6 @@
 
 These settings apply only when `--python` is specified on the command line.
 Please also specify `--python-sdks-folder=<path to the root directory of your azure-sdk-for-python clone>`.
-Use `--python-mode=update` if you already have a setup.py and just want to update the code itself.
-
-
-These settings apply only when `--track2` is specified on the command line.
 
 ``` yaml $(track2)
 azure-arm: true
@@ -20,6 +16,7 @@ clear-output-folder: true
 no-namespace-folders: true
 output-folder: $(python-sdks-folder)/streamanalytics/azure-mgmt-streamanalytics/azure/mgmt/streamanalytics
 ```
+
 ``` yaml $(python-mode) == 'create' && $(track2)
 basic-setup-py: true
 output-folder: $(python-sdks-folder)/streamanalytics/azure-mgmt-streamanalytics