[Pipe Tables Extension] Tables without borders shift cells left if first column empty

[robertwahler]

Parsing is shifting row cells left on this table

a | b
--|--
  | 2

it generates this HTML

<table>
<thead>
<tr>
<th>a</th>
<th>b</th>
</tr>
</thead>
<tbody>
<tr>
<td>2</td>
<td></td>
</tr>
</tbody>
</table>

This bordered table works as expected

| a | b |
|---|---|
|   | 2 |

and generates expected HTML

<table>
<thead>
<tr>
<th>a</th>
<th>b</th>
</tr>
</thead>
<tbody>
<tr>
<td></td>
<td>2</td>
</tr>
</tbody>
</table>