Fixing the log error (#465)

* Fixing the log error

* Adjusting to the feedback:
- deferring the check after the initialization

Author: gmiasnychenko

dask_cloudprovider/gcp/instances.py

@@ -649,8 +649,6 @@ def __init__(
         if not self.ngpus:
             self.scheduler_ngpus = scheduler_ngpus if scheduler_ngpus is not None else self.config.get("scheduler_ngpus", 0)
             self.worker_ngpus = worker_ngpus if worker_ngpus is not None else self.config.get("worker_ngpus", 0)
-            if self.scheduler_ngpus == 0 and self.worker_ngpus == 0:
-                self._log("No GPU instances configured")
         else:
             if scheduler_ngpus is not None or worker_ngpus is not None:
                 raise ValueError("If you specify ngpus, you may not specify scheduler_ngpus or worker_ngpus")
@@ -713,6 +711,9 @@ def __init__(
 
         super().__init__(debug=debug, **kwargs)
 
+        if not self.ngpus and (self.scheduler_ngpus == 0 and self.worker_ngpus == 0):
+            self._log("No GPU instances configured")
+
 
 class GCPCompute:
     """