Error while creating an event with a skip message

[sagar1312]

What happened:
After an event is created via SCM webhook with a skip message "[skip ci]", no builds are created.
In such scenario, the event itself is set as the builds on the event which is incorrect.

#3261 added a logic which iterates the builds that are created after the event to process the workflow for virtual builds. This new logic expects the builds set on the event to be either null or an array.

Due to the above mentioned incorrect the mapping, the new logic is failing with the below error

Error: Failed to start some events caused by \"event.builds.filter is not a function

What you expected to happen:
After the event creation, when the builds are meant to be skipped, set [] as the builds on the event.