This is a breaking change in the way icons are searched. Instead of
specifying just one path and extension, multiple paths and extensions
can be passed. However the field names have changed from singular to
plural.
Fix an error when service.Type is not a field of service_types and the
code attempts to call a nil value.
Turns out that service.Type can be the string "?", probably because
connman has not identified the type yet.
Stefano Mazzucco