git-gui: Report less precise object estimates for database compression

git-gui: Report less precise object estimates for database compression

On startup, git-gui warns if there are many loose objects. It does so by
saying, e.g., that there are "approximately 768 loose objects". But isn't
"768" a very accurate number? Lets say "750", which (while still being a
very precise number) sounds much more like an estimation.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>