semantic-stickyfunc-indent-string

semantic-stickyfunc-indent-string is a variable defined in `util-modes.el'.
Its value is

""

Documentation:
String used to indent the stickyfunc header.
Customize this string to match the space used by scrollbars and
fringe so it does not appear that the code is moving left/right
when it lands in the sticky line.

You can customize this variable.