Merge pull request #17073 from juanvallejo/jvallejo/err-message-fixes-oc-login

Automatic merge from submit-queue.

include err message suggestion oc login err output

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1406066

Outputs an error message suggestion in the event that a user-specified
port is in use by another application / an unexpected response body is found.

```
Response-Body: "123"
$ oc login -u test -p test https://127.0.0.1:9443
The server uses a certificate signed by an unknown authority.
You can bypass the certificate check, but any data you send to the server could be intercepted by others.
Use insecure connections? (y/n): y

error: json: cannot unmarshal number into Go value of type util.OauthAuthorizationServerMetadata - verify you have provided the correct host and port and that the server is currently running
```

```
$ oc login -u test -p test https://127.0.0.1:8443
error: invalid character '<' looking for beginning of value - verify you have provided the correct host and port and that the server is currently running.
```

cc @openshift/cli-review

Author: openshift-merge-robot

pkg/oc/cli/cmd/login/loginoptions.go

@@ -225,14 +225,16 @@ func (o *LoginOptions) gatherAuthInfo() error {
 	clientConfig.KeyFile = o.KeyFile
 	token, err := tokencmd.RequestToken(o.Config, o.Reader, o.Username, o.Password)
 	if err != nil {
+		suggestion := "verify you have provided the correct host and port and that the server is currently running."
+
 		// if internal error occurs, suggest making sure
 		// client is connecting to the right host:port
 		if statusErr, ok := err.(*kerrors.StatusError); ok {
 			if statusErr.Status().Code == http.StatusInternalServerError {
-				return fmt.Errorf("error: The server was unable to respond - verify you have provided the correct host and port and that the server is currently running.")
+				return fmt.Errorf("error: The server was unable to respond - %v", suggestion)
 			}
 		}
-		return err
+		return fmt.Errorf("%v - %v", err, suggestion)
 	}
 	clientConfig.BearerToken = token