Fix: (taxy-magit-section-format-header) Fix alignment

[josephmturner]

In my testing hyperdrive-peer-graph.el, the 1+ misaligned headers.

[alphapapa]

Hi Joseph,

As the FIXME indicates, I do want to resolve this, but at the same time, it was once added for a reason, so it needs to be done carefully. ISTR not long after adding that comment that I noticed an example that made the reason for its presence obvious, but I didn't take the time to document it (maybe something to do with the first or last column, plus depth-based indentation adjustments, etc). So I'm not sure that removing it now would be a net improvement. It would be good to track this in an issue, though, so we could investigate it more thoroughly (apologies for any hint of bureaucratic process, but in released packages, I do try to be very careful and deliberate in changes that might cause problems).

[josephmturner]

All good. I appreciate your caution. Let's reconsider after more testing.