go/printer: revert "make empty lines break table alignment"

This reverts commit c116265e.

The change, while addressing issue #26352, introduced another
regression (#26930), which is worse. Reverting this change in
favor of a better fix for the original issue.

Updates #26352.
Fixes #26930.

Change-Id: I71ad12a8212992cce5c1e73907d1f7460f98d9e8
Reviewed-on: https://go-review.googlesource.com/129255


Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>