zaxisDuplicate: init target attributes (bug fix) .

ChangeLog

+2020-02-20  Uwe Schulzweida
+
+	* zaxisDuplicate: init target attributes (bug fix) [report: Fabian Wachsmann]
+
 2020-02-19  Uwe Schulzweida
 
 	* NetCDF: read lat bounds of a Gaussian reduced grid

src/zaxis.c

@@ -1180,6 +1180,7 @@ int zaxisDuplicate(int zaxisID)
         }
     }
 
+  zaxisptrnew->atts.nelems = 0;
   cdiCopyAtts(zaxisID, CDI_GLOBAL, zaxisIDnew, CDI_GLOBAL);
 
   return zaxisIDnew;