Fixes array_search comparison.

[davidgiga1993]

Test case

A plugin defines a custom -l parameter.
If this parameter is in the first position of the rrdtool_opts array, the default -l argument will still be appended.

Solution

Use === instead of a simple == comparison.
See http://php.net/manual/en/function.array-search.php for more details.

[pommi]

Thanks 👍