Cancelled the XMLHttpRequest timeout callback when the request fails (fixes #348)
Cancelled the XMLHttpRequest timeout callback when the request fails (fixes #348)

juliomenendez/snowplow-javascript-tracker,YieldifyLabs/snowplow-javascript-tracker,fivetran/snowplow-javascript-tracker,juliomenendez/snowplow-javascript-tracker,fivetran/snowplow-javascript-tracker,YieldifyLabs/snowplow-javascript-tracker,snowplow/snowplow-javascript-tracker,YieldifyLabs/snowplow-javascript-tracker,snowplow/snowplow-javascript-tracker,snowplow/snowplow-javascript-tracker,snowplow/snowplow-javascript-tracker,fivetran/snowplow-javascript-tracker,juliomenendez/snowplow-javascript-tracker