Reestablish alignment of pg_controldata output.

Until 9.4, pg_controldata output was all aligned. At some point
during 9.5 development, a new item was added, namely
"Current track_commit_timestamp setting:" which is two characters
too long to be aligned with the rest of the output. Fix this by
removing the noise word "Current" and adding the requisite number
of padding spaces. Since the six preceding items are also similar
in nature, remove "Current" and pad those as well in order to
maintain overall consistency. Backpatch to 9.5 where new offending
item was added.