bug#26553: Possible touch bug

[Paul Eggert]

As mentioned in the coreutils manual under "touch", "'touch' has issues 
similar to those affecting all programs that update file timestamps. For 
example, 'touch' may set a file's timestamp to a value that differs
slightly from the requested time." For more, please see:
https://www.gnu.org/software/coreutils/manual/html_node/File-timestamps.html