Update COPYING (#3231)

Fixed old support URL.

COPYING

@@ -49,7 +49,7 @@ works thereof, in binary and source code form.
 Limited portions of HDF5 were developed by Lawrence Berkeley National 
 Laboratory (LBNL). LBNL's Copyright Notice and Licensing Terms can be
 found here: COPYING_LBNL_HDF5 file in this directory or at 
-http://support.hdfgroup.org/ftp/HDF5/releases/COPYING_LBNL_HDF5. 
+https://raw.githubusercontent.com/hdfgroup/hdf5/develop/COPYING_LBNL_HDF5. 
 
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