According to the vim documentation (:help modeline), the white space
between ':' and the keyword 'set' is optional:
[text]{white}{vi:|vim:|ex:}[white]{options}
[text] any text or empty
{white} at least one blank character ( or )
{vi:|vim:|ex:} the string "vi:", "vim:" or "ex:"
[white] optional white space
{options} a list of option settings, separated with white space or ':',
where each part between ':' is the argument for a ":set"
command (can be empty)
Thus, the regular expression has been changed to match zero or more
white spaces, rather than one or more.
According to the vim documentation (:help modeline), the white space between ':' and the keyword 'set' is optional:
[text] any text or empty {white} at least one blank character ( or )
{vi:|vim:|ex:} the string "vi:", "vim:" or "ex:"
[white] optional white space
{options} a list of option settings, separated with white space or ':',
where each part between ':' is the argument for a ":set"
command (can be empty)
Thus, the regular expression has been changed to match zero or more white spaces, rather than one or more.