ovpnmain.cgi: Fix for bug 13030 - Table style rendering bug

ovpnmain.cgi: Fix for bug 13030 - Table style rendering bug

- In six places <td class'base'> has been used instead of <td class='base'>
- This patch fixes that error - tested on my vm testbed. Selecting Inspect Element now
   shows the corrrect result rather than class 'base' being set to null.

Tested-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Bernhard Bitsch <bbitsch@ipfire.org>