fix: avoid possible nil logger when calculating block name

[tim775]

From sentry:

runtime error: invalid memory address or nil pointer dereference
"stacktrace": 
"1: running [Created by terraform.(*HCLProvider).Modules @ hcl_provider.go:339]
   :24                                                             Stack()
   :289                                                            (*Parser).ParseDirectory.func1()
   :884                                                            panic()
   :126                                                            (*Entry).WithFields()
   :121                                                            (*Entry).WithField()
   :107                                                            (*Entry).WithError()
   :980                                                            (*Block).Reference()
   :991                                                            (*Block).LocalName()
   :1015                                                           (*Block).FullName()
   :628                                                            (*Block).setLogger()
   :303                                                            BlockBuilder.NewBlock()
   :284                                                            BlockBuilder.NewBlock()
   :284                                                            BlockBuilder.NewBlock()