Not sure what side effects this may have. Was first solving this in MediaAnayltics to prevent notices such as:
WARNING MediaAnalytics[2019-09-23 19:22:13 UTC] [3489 ...] Trying to add two strings in DataTable\Row::sumRowArray: https:/... + https://...) for column url in row # ['label' => -1, 'nb_plays' => 8, 'nb_unique_visitors_plays' => 3, 'nb_impressions' => 80, 'nb_unique_visitors_impressions' => 47, 'nb_finishes' => 5, 'sum_media_length' => 120, 'sum_time_watched' => 87, 'sum_time_to_play' => 10, 'sum_time_progress' => 84, 'nb_plays_with_tip' => 8, 'nb_plays_with_ml' => 8, 'sum_fullscreen_plays' => 0, 'url' => 'https://...']  [idsubtable = ]
but then also noticed this problem in other plugins such as Funnels. Maybe that fixes it for all plugins considering
url is a common column maybe in Matomo and it shouldn't be summable?
Actually, the url column should be metadata so it shouldn't be summed there