changelog for error message dedent

also fix changelog for #1528

Author: alexcjohnson

CHANGELOG.md

@@ -12,6 +12,10 @@ to close the error messages box.
 - [#1503](https://github.com/plotly/dash/pull/1506) Fix [#1466](https://github.com/plotly/dash/issues/1466): loosen `dash[testing]` requirements for easier integration in external projects. This PR also bumps many `dash[dev]` requirements.
 
 ### Fixed
+- [#1530](https://github.com/plotly/dash/pull/1530) Dedent error messages more carefully.
+- [#1527](https://github.com/plotly/dash/issues/1527)🐛 `get_asset_url` now pulls from an external source if `assets_external_path` is set.
+  - updated `_add_assets_resource` to build asset urls the same way as `get_asset_url`.
+  - updated doc string for `assets_external_path` Dash argument to be more clear that it will allways be joined with the `assets_url_path` argument when determining the url to an external asset.
 - [#1493](https://github.com/plotly/dash/pull/1493) Fix [#1143](https://github.com/plotly/dash/issues/1143), a bug where having a file with one of several common names (test.py, code.py, org.py, etc) that imports a dash component package would make `import dash` fail with a cryptic error message asking whether you have a file named "dash.py"
 
 ## [1.18.1] - 2020-12-09
@@ -695,9 +699,3 @@ app = dash.Dash(...)
 
 ## 0.17.3 - 2017-06-22
 ✨ This is the initial open-source release of Dash.
-
-### Fixed
-- [#1527](https://github.com/plotly/dash/issues/1527)🐛 `get_asset_url` now pulls from an external source if `assets_external_path` is set.
-- updated `_add_assets_resource` to build asset urls the same way as `get_asset_url`.
-- updated doc string for `assets_external_path` Dash argument to be more clear that it will allways be joined with 
-the `assets_url_path` argument when determining the url to an external asset.