PHP supports sending/parsing multidimensional arrays in the URL, eg:

param[key1][key2][] = 12

which would be parsed as:

[
    'key1' => [
        'key2' => [
            12,
        ],
    ],
]

Python does not, so if you're replaying logs for a plugin that uses multidimensional array tracker query parameters, the replay will fail.

This fixes the issue by converting such parameters manually. Tried also to convert the parsed query string back into a query string (which would have been far simpler), but python 2 has trouble with converting querystrings with unicode.

Note: I tried converting the string parts to unicode before calling urllib.urlencode() (as suggested here: https://stackoverflow.com/questions/6480723/urllib-urlencode-doesnt-like-unicode-values-how-about-this-workaround), but that results in odd test failures in ImportLogsTest.php. This change doesn't.

Core build for this PR is here: https://travis-ci.org/matomo-org/matomo/builds/372841147