Incorrect output when multiple transition properties are used

[jarektomanek]

Source CSS:

.example {
    transition: filter 1s, transform 2s;
}

Output:

.example {
    transition: -webkit-filter 1s, -webkit-transform 2s, filter 1s, -webkit-transform 2s;
}

Issue:
"-webkit-transform 2s" is listed twice, while "transform 2s" is not listed at all.

Config: browsers: ['last 2 versions']
grunt-autoprefixer version: 3.0.4