BEAST2.7.3 bash script requires to set "$LD_LIBRARY_PATH" in env

[walterxie]

https://github.com/CompEvol/beast2/blob/master/release/Linux/jrebin/beast relies on uname -m returning "x86_64", and then defines "$LD_LIBRARY_PATH" required to launch BEAST. But in M1 chip, it returns "arm64", so the user has to set "$LD_LIBRARY_PATH" in env to make beast work properly.

Suggest:

Add the process to set "$LD_LIBRARY_PATH" in else, so the script can still work using different CPU. The previous code in beast2.6.7 will work in the else section, just add $BEAST_EXTRA_LIBS to $LD_LIBRARY_PATH, e.g. export LD_LIBRARY_PATH="$LD_LIBRARY_PATH":/usr/local/lib:$HOME/lib:$BEAST_EXTRA_LIBS