mtimeout.1: Use correct dash for number ranges.

[misc] / spacetest

          <- 10 spaces
                <- two tabs
        <- space space tab, space -> 
foo ->  <- space tab
foo ->          <- tab and eight spaces
waffle> <- one space
stuff.  <- two spaces
blah.   <- three spaces
blah.    <- four spaces
stuff-  <- two spaces
eof ->