sessions: Remove odata.context

Redfish made odata.context optional (1.6.0 of DSP0266, Sept 2018).
Redfish has removed odata.context from example payloads in the
specification (1.7.0 of DSP0266), removed it from the mockups,
and Redfish recommended not using.

Change-Id: Iffc75a7cb68f22d67548e5632d7ebfbdd67d6598
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/redfish-core/lib/redfish_sessions.hpp b/redfish-core/lib/redfish_sessions.hpp
index 0094858..c3e11a3 100644
--- a/redfish-core/lib/redfish_sessions.hpp
+++ b/redfish-core/lib/redfish_sessions.hpp
@@ -61,8 +61,6 @@
         res.jsonValue["@odata.id"] =
             "/redfish/v1/SessionService/Sessions/" + session->uniqueId;
         res.jsonValue["@odata.type"] = "#Session.v1_0_2.Session";
-        res.jsonValue["@odata.context"] =
-            "/redfish/v1/$metadata#Session.Session";
         res.jsonValue["Name"] = "User Session";
         res.jsonValue["Description"] = "Manager User Session";
 
@@ -160,8 +158,6 @@
         res.jsonValue["Members@odata.count"] = sessionIds.size();
         res.jsonValue["@odata.type"] = "#SessionCollection.SessionCollection";
         res.jsonValue["@odata.id"] = "/redfish/v1/SessionService/Sessions/";
-        res.jsonValue["@odata.context"] =
-            "/redfish/v1/$metadata#SessionCollection.SessionCollection";
         res.jsonValue["Name"] = "Session Collection";
         res.jsonValue["Description"] = "Session Collection";
         res.end();
@@ -244,8 +240,6 @@
     {
         res.jsonValue["@odata.type"] = "#SessionService.v1_0_2.SessionService";
         res.jsonValue["@odata.id"] = "/redfish/v1/SessionService/";
-        res.jsonValue["@odata.context"] =
-            "/redfish/v1/$metadata#SessionService.SessionService";
         res.jsonValue["Name"] = "Session Service";
         res.jsonValue["Id"] = "SessionService";
         res.jsonValue["Description"] = "Session Service";