Update sites.json

line 268: added german translation for Daily Mile.
line 303: missing english description for DeviantArt (german was marked as english-description). fixed.
line 313: missing english descriotion for DHL (Paket.de) (german was marked as english-description). fixed.
line 377: added german translation for Dwolla.
line 474: added german translation for Fitoracy.
line 491: added german translation for Flipboard.
line 523: added german translation for Freelancer.
line 557: added german translation for Gauges.
line 625: added german translation for Glassdoor.
line 635: added german translation for GMX.