HPCC-17877 Fix Roxie SSL exception - check_connection not implemented

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>

system/security/securesocket/securesocket.cpp

@@ -377,7 +377,7 @@ public:
 
     virtual bool check_connection()
     {
-        throw MakeStringException(-1, "CSecureSocket::check_connection: not implemented");
+        return m_socket->check_connection();
     }
 
     virtual bool isSecure() const override