Conditional enable the ldap configuration

If any of the existing ldap config(openldap/AD) is
already enabled,The other ldap configuration can't be
enabled.

TestedBy: Unit-Tested

          Tested the above behaviour.It throws the
          error back if try to enable the configuration
          when there is already active configuration.

          If there is no active configuration then it
          allows to enable the configuration.

Signed-off-by: Ratan Gupta <ratagupt@linux.vnet.ibm.com>
Change-Id: I5b6008036152cd36e5422bb372a05c8a3ec3d24b
diff --git a/phosphor-ldap-config/ldap_config_mgr.hpp b/phosphor-ldap-config/ldap_config_mgr.hpp
index 812528b..dc04546 100644
--- a/phosphor-ldap-config/ldap_config_mgr.hpp
+++ b/phosphor-ldap-config/ldap_config_mgr.hpp
@@ -102,6 +102,11 @@
     /** @brief Populate existing config into D-Bus properties
      */
     virtual void restore();
+    /** @brief enable/disable the ldap service
+     *  @param[in] config - config  which needs to be enabled/disabled
+     *  @param[in] value - boolean value to start/stop
+     */
+    bool enableService(Config& config, bool value);
 
     /* ldap service enabled property would be saved under
      * this path.