Update behavior for the ssh config/ca endpoint when a CA exists

 - The docs mentioned that the values would be overwritten but we
   actually error out to the end user, telling them they must delete
   before the update will take place. Update our docs to match the code.

Author: stevendpclark

content/vault/v1.16.x/content/api-docs/secret/ssh.mdx

@@ -558,8 +558,12 @@ $ curl \
 ## Submit CA information
 
 This endpoint allows submitting the CA information for the secrets engine via an SSH
-key pair. _If you have already set a certificate and key, they will be
-overridden._
+key pair. 
+
+<Note>
+If a certificate or key are present, an error will be returned. To update the existing
+values, the Delete CA information API will need to be called first.
+</Note>
 
 | Method | Path             |
 | :----- | :--------------- | -------------------------- |

content/vault/v1.17.x/content/api-docs/secret/ssh.mdx

@@ -562,8 +562,12 @@ $ curl \
 ## Submit CA information
 
 This endpoint allows submitting the CA information for the secrets engine via an SSH
-key pair. _If you have already set a certificate and key, they will be
-overridden._
+key pair. 
+
+<Note>
+If a certificate or key are present, an error will be returned. To update the existing
+values, the Delete CA information API will need to be called first.
+</Note>
 
 | Method | Path             |
 | :----- | :--------------- | -------------------------- |

content/vault/v1.18.x/content/api-docs/secret/ssh.mdx

@@ -562,8 +562,12 @@ $ curl \
 ## Submit CA information
 
 This endpoint allows submitting the CA information for the secrets engine via an SSH
-key pair. _If you have already set a certificate and key, they will be
-overridden._
+key pair. 
+
+<Note>
+If a certificate or key are present, an error will be returned. To update the existing
+values, the Delete CA information API will need to be called first.
+</Note>
 
 | Method | Path             |
 | :----- | :--------------- | -------------------------- |

content/vault/v1.19.x/content/api-docs/secret/ssh.mdx

@@ -559,8 +559,12 @@ $ curl \
 ## Submit CA information
 
 This endpoint allows submitting the CA information for the secrets engine via an SSH
-key pair. _If you have already set a certificate and key, they will be
-overridden._
+key pair. 
+
+<Note>
+If a certificate or key are present, an error will be returned. To update the existing
+values, the Delete CA information API will need to be called first.
+</Note>
 
 | Method | Path             |
 | :----- | :--------------- | -------------------------- |

content/vault/v1.20.x/content/api-docs/secret/ssh.mdx

@@ -559,8 +559,12 @@ $ curl \
 ## Submit CA information
 
 This endpoint allows submitting the CA information for the secrets engine via an SSH
-key pair. _If you have already set a certificate and key, they will be
-overridden._
+key pair. 
+
+<Note>
+If a certificate or key are present, an error will be returned. To update the existing
+values, the Delete CA information API will need to be called first.
+</Note>
 
 | Method | Path             |
 | :----- | :--------------- | -------------------------- |