Add support to request a single Journal Event Log Entry

This change adds back support to request a single Journal Event
Log Entry.

Tested:
Requested a single valid entry and got it.
Requested an invalid entry and got the correct error message.
Passed the Redfish Service Validator.

Change-Id: Ibd2defee04510c1b52fe010cf3e2c6aced94537f
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
diff --git a/redfish-core/include/redfish.hpp b/redfish-core/include/redfish.hpp
index 21d6500..6f68611 100644
--- a/redfish-core/include/redfish.hpp
+++ b/redfish-core/include/redfish.hpp
@@ -86,6 +86,7 @@
 #ifndef BMCWEB_ENABLE_REDFISH_DBUS_LOG_ENTRIES
         nodes.emplace_back(
             std::make_unique<JournalEventLogEntryCollection>(app));
+        nodes.emplace_back(std::make_unique<JournalEventLogEntry>(app));
 #endif
 
         nodes.emplace_back(std::make_unique<BMCLogServiceCollection>(app));