updated hdf5 version

external/hdf5/install_hdf5.sh

-hdf5_version=1.10.2
+hdf5_version=1.10.3
 if [ ! -r CMake-hdf5-${hdf5_version} ]
 then
     #Get the file with the code

[Matthias Redies]

This version seems to build in gfortran, whereas 1.10.3 didn't seem to work.