Rest Cheatsheet: Remove Content-Type on GET request

There is no "Content-Type" on GET request.

Content-Type is only used with POST and PUT requests. See:
https://en.wikipedia.org/wiki/List_of_HTTP_header_fields

Change-Id: Ic927eaaa95aa2eee92791032bc631a1623602e90
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/REST-cheatsheet.md b/REST-cheatsheet.md
index 7067105..3bd1abb 100644
--- a/REST-cheatsheet.md
+++ b/REST-cheatsheet.md
@@ -11,14 +11,14 @@
 
 * List and enumerate:
     ```
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" https://${bmc}/xyz/openbmc_project/list
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" https://${bmc}/xyz/openbmc_project/enumerate
+    $ curl -c cjar -b cjar -k https://${bmc}/xyz/openbmc_project/list
+    $ curl -c cjar -b cjar -k https://${bmc}/xyz/openbmc_project/enumerate
     ```
 
 * List sub-objects:
     ```
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" https://${bmc}/xyz/openbmc_project/
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" https://${bmc}/xyz/openbmc_project/state/
+    $ curl -c cjar -b cjar -k https://${bmc}/xyz/openbmc_project/
+    $ curl -c cjar -b cjar -k https://${bmc}/xyz/openbmc_project/state/
     ```
 
 * Host soft power off:
@@ -102,8 +102,8 @@
 
     - Read:
     ```
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" -X GET https://${bmc}/xyz/openbmc_project/time/owner/attr/TimeOwner
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" -X GET https://${bmc}/xyz/openbmc_project/time/sync_method/attr/TimeSyncMethod
+    $ curl -c cjar -b cjar -k -X GET https://${bmc}/xyz/openbmc_project/time/owner/attr/TimeOwner
+    $ curl -c cjar -b cjar -k -X GET https://${bmc}/xyz/openbmc_project/time/sync_method/attr/TimeSyncMethod
     ```
     - Write:
     ```
@@ -126,7 +126,7 @@
     or
 
     ```
-    $ curl -c cjar -b cjar -k -H "Content-Type: application/json" -X GET https://${bmc}/xyz/openbmc_project/control/power_supply_redundancy
+    $ curl -c cjar -b cjar -k -X GET https://${bmc}/xyz/openbmc_project/control/power_supply_redundancy
     ```
 
     - Write (Enable/Disable):