TLS-configuration: Fix Content-Type spelling

Spelled Content-Type:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type

Without this change going to think it is a different header.

```
> ContentType:application/json
> Content-Length: 48
> Content-Type: application/x-www-form-urlencoded
```

Change-Id: Iceba2b53be5ec8ce1f0058d133af6906a9687b6a
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/security/TLS-configuration.md b/security/TLS-configuration.md
index fddb1b8..b75258b 100644
--- a/security/TLS-configuration.md
+++ b/security/TLS-configuration.md
@@ -408,13 +408,13 @@
 To enable TLS authentication use this command:
 
 ```
-curl --user root:0penBmc  -k -X PATCH -H "ContentType:application/json" --data '{"Oem": {"OpenBMC": {"AuthMethods": { "TLS": true} } } }' https://${bmc}/redfish/v1/AccountService
+curl --user root:0penBmc  -k -X PATCH -H "Content-Type: application/json" --data '{"Oem": {"OpenBMC": {"AuthMethods": { "TLS": true} } } }' https://${bmc}/redfish/v1/AccountService
 ```
 
 To disable TLS authentication use this command:
 
 ```
-curl --user root:0penBmc  -k -X PATCH -H "ContentType:application/json" --data '{"Oem": {"OpenBMC": {"AuthMethods": { "TLS": false} } } }' https://${bmc}/redfish/v1/AccountService
+curl --user root:0penBmc  -k -X PATCH -H "Content-Type: application/json" --data '{"Oem": {"OpenBMC": {"AuthMethods": { "TLS": false} } } }' https://${bmc}/redfish/v1/AccountService
 ```
 
 Other authentication methods like basic authentication can be enabled or