CASMTRIAGE-7215 Update prepare_site_init.md (#5304)

* Update prepare_site_init.md

Signed-off-by: ganesh s <124240773+ganeshs-hpe@users.noreply.github.com>
(cherry picked from commit 80d5971)

* Update prepare_site_init.md

Signed-off-by: ganesh s <124240773+ganeshs-hpe@users.noreply.github.com>
(cherry picked from commit 0c79fc7)

* Update install/prepare_site_init.md

Signed-off-by: Russell Bunch <doomslayer@hpe.com>
(cherry picked from commit ac690b0)

* Update install/prepare_site_init.md

Signed-off-by: Nathan Rockershousen <nathan.rockershousen@hpe.com>
(cherry picked from commit ea0b13f)

---------

Co-authored-by: ganesh s <124240773+ganeshs-hpe@users.noreply.github.com>
Co-authored-by: Russell Bunch <doomslayer@hpe.com>
Co-authored-by: Nathan Rockershousen <nathan.rockershousen@hpe.com>

install/prepare_site_init.md

@@ -238,6 +238,13 @@ with system-specific customizations.
             -keystore /data/certs.jks -storepass password -noprompt
     ```
 
+    > **`NOTE`** If the command is executed multiple times by oversight, then the console will display the following and may be ignored
+    > to proceed further.
+
+    ```text
+    keytool error: java.lang.Exception: Certificate not imported, alias <cray-data-center-ca> already exists
+    ```
+
 1. (`pit#`) Create `certs.jks.b64` by base-64 encoding `certs.jks`.
 
     ```bash