Fix a bug about getting callerId

:Release Notes:
Fix a bug about getting callerId

:Detailed Notes:
SAM gets callers' ID by using LS2 interface.
Normally, it should be one of below items.

1. application
2. service

However, sometimes, it is null.
This commit checks returnValue from those APIs
and assign 'unknown' if there is nothing.

:Testing Performed:
- network disconnect
- launch youtube
- click 'NETWORK SETTINGS'
- Settings works well

:Issues Addressed:
[PLAT-102158] [webOS Auto]:Network Connection Error page
              functionality is not working

Change-Id: Ief321c97e43b88e1e7a89ff578eb06e4157ef5cd
Reviewed-on: http://gpro.lge.com/c/webosose/sam/+/271209
Tested-by: Sangwoo Kang <[email protected]>
Reviewed-by: Sangwoo Kang <[email protected]>

src/base/LunaTask.h

@@ -152,8 +152,10 @@ friend class LunaTaskList;
     {
         if (m_request.getApplicationID() != nullptr) {
             return m_request.getApplicationID();
-        } else {
+        } else if (m_request.getSenderServiceName() != nullptr){
             return m_request.getSenderServiceName();
+        } else {
+            return "unknown";
         }
     }