Fixed crash on iOS if error description is not attached to the event.
Fixed crash on iOS if error description is not attached to the event.

ptarjan/cordova-hot-code-push,ptarjan/cordova-hot-code-push,limexcomputer/cordova-hot-code-push,ptarjan/cordova-hot-code-push,nordnet/cordova-hot-code-push,davidovich/cordova-hot-code-push,limexcomputer/cordova-hot-code-push,davidovich/cordova-hot-code-push,nordnet/cordova-hot-code-push,mnewmedia/cordova-hot-code-push,mnewmedia/cordova-hot-code-push