MT#59962 DSM: initialize DSMScriptConfig diags to NULL

Just initialize to NULL before going forward.

Fixes:

    CID 542426: (#1 of 1): Uninitialized pointer read (UNINIT)
    21. uninit_use_in_call: Using uninitialized value script_config.diags when calling operator =

Change-Id: I4ed97e4fbeb371f04f0496565fa03b7b4a302e02

apps/dsm/DSM.cpp

@@ -417,6 +417,7 @@ bool DSMFactory::loadConfig(const string& conf_file_name, const string& conf_nam
     return false;
 
   DSMScriptConfig script_config;
+  script_config.diags = NULL;
   script_config.RunInviteEvent = 
     cfg.getParameter("run_invite_event")=="yes";