Bad configurations can cause webtracking code in various connectors to crash web set

Description

Steps to reproduce
(cause any type of error with the configuration - corrupt, use machine encryption then change it, anything)
In a load balanced environment, content author machine

1) Configure the Silverpop connector - (no injection script, not relevant to the error).
2) Create a form and verify that it works.
3) On the load balance machine, verify that the form works.

Expected:
The form works and scripts get injected.

Actual:
Stack Trace:
[NullReferenceException: Object reference not set to an instance of an object.] Episerver.Marketing.Connector.Silverpop.WebTrackingInjection.RegisterResources(IRequiredClientResourceList requiredResources) +604
System.Collections.Generic.List`1.ForEach(Action`1 action) +99