[core] remove function declaration without implementation (#1991)

The implementation was removed in a previous PR.

Author: KerstinKeller

ecal/core/include/ecal/config.h

@@ -95,13 +95,6 @@ namespace eCAL
     /////////////////////////////////////
 
     ECAL_API std::string              GetEcalSysFilterExcludeList          ();
-
-    /////////////////////////////////////
-    // publisher
-    /////////////////////////////////////
-    
-    ECAL_API bool                     IsTopicTypeSharingEnabled            ();
-    ECAL_API bool                     IsTopicDescriptionSharingEnabled     ();
 
     /////////////////////////////////////
     // subscriber