doc: this extra newline caused the last table cell to be misaligned.

Because Doxygen (or maybe m.css?) added an extra <p> there, ruining the
CSS alignment class. WEBDEV.

doc/file-formats.dox

@@ -293,7 +293,6 @@ Together with @ref file-formats-scene-importers "scene importers" derived from
 <td class="m-text-center m-danger">external</td>
 <td class="m-text-center m-success">BSD 3-clause</td>
 </tr>
-
 </table>
 
 @endparblock