piwik.js: configTrackerUrl cannot contain a "?" for GET request method #2115

if the configTrackerUrl contains a "?" line 1008 in piwik.js should append a "&" instead of another "?"

proposed change :

• image.src = configTrackerUrl + '?' + request;
• image.src = configTrackerUrl + (configTrackerUrl.match(/[?]/) ? '&' : '?') + request;

PS: I kindof need this to integrate piwik in a CMS. I can find my way around though.

(In [3981]) fixes #2115