itemsPerMinute errors should include IP address

[waltjones]

When the itemsPerMinute threshold is exceeded in the browser, a specific itemsPerMinute error event is sent and further Rollbar events are discarded until the timer expires. This happens on a per browser basis.

Currently the itemsPerMinute error doesn't include the IP address in the payload. Rollbar items can be filtered by IP address, but only when it's present. Adding this would allow easily finding the cause of the exceeded threshold. In the item list filtered by IP, you could simply look at what error(s) preceded the itemsPerMinute error.

Without this improvement, you need to browse through all project items by timestamp until you locate the place in history where the itemsPerMinute error occurred.