wrong grid for LM external parameters for ERA5 – in #10: INT2LM

in #10: INT2LM

<pre> startlat_tot = -16.99, startlon_tot = -19.99, </pre> <p> may work </p>

  @burkhardtrockel in #83c95d7

<pre> startlat_tot = -16.99, startlon_tot = -19.99, </pre> <p> may work </p>
startlat_tot  = -16.99, startlon_tot  = -19.99,

may work