chore: assign default params to host, port parameters in Dash.run()

Author: martian0x80

CHANGELOG.md

@@ -13,6 +13,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - [#2898](https://github.com/plotly/dash/pull/2898) Fix error thrown when using non-existent components in callback running keyword. Fixes [#2897](https://github.com/plotly/dash/issues/2897).
 - [#2892](https://github.com/plotly/dash/pull/2860) Fix ensures dcc.Dropdown menu maxHeight option works with Datatable. Fixes [#2529](https://github.com/plotly/dash/issues/2529) [#2225](https://github.com/plotly/dash/issues/2225)
 - [#2896](https://github.com/plotly/dash/pull/2896) The tabIndex parameter of Div can accept number or string type. Fixes [#2891](https://github.com/plotly/dash/issues/2891)
+- [#2908](https://github.com/plotly/dash/pull/2908) Fix when environment variables are ignored by Dash.run() at runtime. Fixes [#2902](https://github.com/plotly/dash/issues/2902)
 
 ## [2.17.1] - 2024-06-12
 

dash/dash.py

@@ -1981,8 +1981,8 @@ def delete_resource(resources):
 
     def run(
         self,
-        host=None,
-        port=None,
+        host="127.0.0.1",
+        port="8050",
         proxy=None,
         debug=None,
         jupyter_mode: JupyterDisplayMode = None,