Improve the error message displayed when there is a webserver error (#…

…36570)

The error message displayed when errors happen in the webserver did
not properly communicated, that the user MUST look at the logs and
provide more information to investigate the root cause (after looking
at the logs themselves). We have a number of users just copy&pasting
the generic error message without understanding that this is not nearly
enough to help them.

This PR proposes a bit more explicit call to look at the logs and
explains why details are not displayed (for security reasons).

(cherry picked from commit 574f86e)

airflow/www/templates/airflow/traceback.html

@@ -27,25 +27,24 @@
       <h1> Ooops! </h1>
       <div>
           <pre>
-Something bad has happened.
+Something bad has happened. For security reasons detailed information about the error is not logged.
 
-Airflow is used by many users, and it is very likely that others had similar problems and you can easily find
-a solution to your problem.
+  * You should check your webserver logs and retrieve details of this error.
 
-Consider following these steps:
+  * When you get the logs, it might explain the reasons, you should also Look for similar issues using:
 
-  * gather the relevant information (detailed logs with errors, reproduction steps, details of your deployment)
-
-  * find similar issues using:
      * <b><a href="https://github.com/apache/airflow/discussions">GitHub Discussions</a></b>
      * <b><a href="https://github.com/apache/airflow/issues">GitHub Issues</a></b>
      * <b><a href="https://stackoverflow.com/questions/tagged/airflow">Stack Overflow</a></b>
      * the usual search engine you use on a daily basis
 
+    All those resources might help you to find a solution to your problem.
+
   * if you run Airflow on a Managed Service, consider opening an issue using the service support channels
 
-  * if you tried and have difficulty with diagnosing and fixing the problem yourself, consider creating a <b><a href="https://github.com/apache/airflow/issues/new/choose">bug report</a></b>.
-    Make sure however, to include all relevant details and results of your investigation so far.
+  * only after you tried it all, and have difficulty with diagnosing and fixing the problem yourself,
+    get the logs with errors, describe results of your investigation so far, and consider creating a
+    <b><a href="https://github.com/apache/airflow/issues/new/choose">bug report</a></b> including this information.
 
 Python version: {{ python_version }}
 Airflow version: {{ airflow_version }}