[core] Fix a memory leak in an unlikely error condition
[core] Fix a memory leak in an unlikely error condition

Pecisk/libgdata-gtasks,Distrotech/libgdata,Pecisk/libgdata,Distrotech/libgdata,Pecisk/libgdata,pwithnall/libgdata,Pecisk/libgdata-gtasks,Pecisk/libgdata,Distrotech/libgdata,GNOME/libgdata,pwithnall/libgdata,Pecisk/libgdata-gtasks