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

lib/database.tcl

@@ -102,8 +102,8 @@ proc hint_gc {} {
 		*]]
 
 	if {$objects_current >= $object_limit} {
-		set objects_current [expr {$objects_current * 256}]
-		set object_limit    [expr {$object_limit    * 256}]
+		set objects_current [expr {$objects_current * 250}]
+		set object_limit    [expr {$object_limit    * 250}]
 		if {[ask_popup \
 			[mc "This repository currently has approximately %i loose objects.