(DOCSP-25126) Change note and remove settings re: backwards support for concatenated pem secrets (#1052)

* (DOCSP-25126) Change note re: backwards support for concatenated pem secrets

* Removes deprecated settings

* Revert "Removes deprecated settings"

This reverts commit 413e2cd3c6b80f03b5b24f94baca3483ae68cd16.

Author: sarahsimpers

source/includes/prereqs/pem-format.rst

@@ -1,22 +1,13 @@
 .. important::
 
-   For fresh |k8s-op-short| installations starting with version 1.13, 
-   the |k8s-op-short| uses :k8sdocs:`kubernetes.io/tls
+   The |k8s-op-short| uses :k8sdocs:`kubernetes.io/tls
    </concepts/configuration/secret/#tls-secrets>` secrets
    to store |tls| certificates and private keys for |onprem| and MongoDB
-   resources.
+   resources. Starting in |k8s-op-short| version 1.17, the 
+   |k8s-op-short| doesn't support concatenated |pem| files stored as    :k8sdocs:`Opaque secrets </concepts/configuration/secret/#opaque-secrets>`. 
 
-   Previous |k8s-op-short| versions required you to concatenate your
-   |tls| certificates and private keys into a |pem| file and store this
-   file in an
-   :k8sdocs:`Opaque </concepts/configuration/secret/#opaque-secrets>` 
-   secret. 
-
-   To maintain backwards compatibility, the |k8s-op-short|
-   continues to support storing |pem| files in Opaque secrets. Support
-   of this feature might be removed in a future release.
-
-   We recommend that you upgrade to |k8s-op-short| version 1.15.1 
-   or later.
+   To migrate your |pem| files stored as Opaque secrets |tls| secrets to :k8sdocs:`kubernetes.io/tls 
+   </concepts/configuration/secret/#tls-secrets>` secrets, see
+   :ref:`migrate-to-new-tls-format`.
 
    .. include:: /includes/fact-broken-appdb.rst