Remove NULL ptr for shared_ptr initialization, conflict on old compiler
Remove NULL ptr for shared_ptr initialization, conflict on old compiler

EricKTCheung/davix,EricKTCheung/davix,EricKTCheung/davix,cern-it-sdc-id/davix,cern-it-sdc-id/davix,cern-it-sdc-id/davix,EricKTCheung/davix,cern-it-sdc-id/davix