Update current.tmpl

Change the short description by the long description in the current event. The short description was empty, the change from the long description and looks better than a short description...

Change:
      <td colspan="3">$tstrings['description']:  $getVar("now.shortdesc", " ")</td>

By:
      <td colspan="3">$tstrings['description']:  $getVar("now.longdesc", " ")</td>