bug#29589: date %k adds extra space for single digits hours

[Noam Arad]

When using date command with the format %k if the hour is single digits there 
is an extra space added.
E.g.: date -u +"%Y/%m/%d %k:%M:%S" when run at "2017/12/06 9:16:26" will give 
the output "2017/12/06  9:16:26"
NOTE: there are two spaces between "06" and "9".

Thanks