Fix error message's link for column mapping usage (#830)

# Description

[PR](https://github.com/microsoft/promptflow/pull/651/files) changed
link path, so the error message is not valid.
Replace link by aka link.
Then we only need to update redirection rule after changing link

# All Promptflow Contribution checklist:
- [X] **The pull request does not introduce [breaking changes].**
- [ ] **CHANGELOG is updated for new features, bug fixes or other
significant changes.**
- [X] **I have read the [contribution guidelines](../CONTRIBUTING.md).**
- [X] **Create an issue and link to the pull request to get dedicated
review from promptflow team. Learn more: [suggested
workflow](../CONTRIBUTING.md#suggested-workflow).**

## General Guidelines and Best Practices
- [X] Title of the pull request is clear and informative.
- [ ] There are a small number of commits, each of which have an
informative message. This means that previously merged commits do not
appear in the history of the PR. For more information on cleaning up the
commits in your PR, [see this
page](https://github.com/Azure/azure-powershell/blob/master/documentation/development-docs/cleaning-up-commits.md).

### Testing Guidelines
- [ ] Pull request includes test coverage for the included changes.

Co-authored-by: Robben Wang <[email protected]>

src/promptflow/promptflow/executor/flow_executor.py

@@ -798,8 +798,7 @@ def validate_and_apply_inputs_mapping(self, inputs, inputs_mapping) -> List[Dict
             logger.warning(
                 msg=(
                     "Starting run without column mapping may lead to unexpected results. "
-                    "Please consult the following documentation for more information: "
-                    "https://microsoft.github.io/promptflow/how-to-guides/column-mapping.html."
+                    "Please consult the following documentation for more information: https://aka.ms/pf/column-mapping"
                 )
             )
 
@@ -1054,8 +1053,7 @@ def apply_inputs_mapping(
                 message_format=(
                     "The input for batch run is incorrect. Couldn't find these mapping relations: {invalid_relations}. "
                     "Please make sure your input mapping keys and values match your YAML input section and input data. "
-                    "For more information, refer to the following documentation: "
-                    "https://microsoft.github.io/promptflow/how-to-guides/column-mapping.html."
+                    "For more information, refer to the following documentation: https://aka.ms/pf/column-mapping"
                 ),
                 invalid_relations=invalid_relations,
             )