Add the check for the existense of the client

Don't add the client if it is already configured.

Change-Id: Ib0c64e2eb73b272a290599e1b83630a8ab5709ec
Signed-off-by: Ratan Gupta <ratagupt@linux.vnet.ibm.com>
diff --git a/snmp_conf_manager.hpp b/snmp_conf_manager.hpp
index f477b31..de9e486 100644
--- a/snmp_conf_manager.hpp
+++ b/snmp_conf_manager.hpp
@@ -63,6 +63,15 @@
      */
     void restoreClients();
 
+    /** @brief Check if client is already configured or not.
+     *
+     *  @param[in] address - SNMP manager address.
+     *  @param[in] port -    SNMP manager port.
+     *
+     *  @return throw exception if client is already configured.
+     */
+    void checkClientConfigured(const std::string& address, uint16_t port);
+
     /** @brief location of the persisted D-Bus object.*/
     fs::path dbusPersistentLocation;