absolute path to maxctrl.js in binary tarball bin/maxscale script

The bin/maxscale script in binary tarballs contains an absolute path to the maxscale.js javascript code file:

 $NODECMD "/usr/share/maxscale/maxctrl/maxctrl.js" "$@"

With that maxctrl can only work if either the tarball gets extracted into the root directory, not in a different path like e.g. /usr/local/maxscale, or if the share/maxscale directory gets symlinked from the custom path to /usr/share/maxscale