Bugfix for gc_storage and s3

Make keysum return None if not key_check (this case wasn't covered).

cloud/gc_storage

@@ -152,7 +152,8 @@ def key_check(module, gs, bucket, obj):
 def keysum(module, gs, bucket, obj):
     bucket = gs.lookup(bucket)
     key_check = bucket.get_key(obj)
-    if key_check:
+    if not key_check:
+        return None
     md5_remote = key_check.etag[1:-1]
     etag_multipart = '-' in md5_remote # Check for multipart, etag is not md5
     if etag_multipart is True:

cloud/s3

@@ -145,7 +145,8 @@ def key_check(module, s3, bucket, obj):
 def keysum(module, s3, bucket, obj):
     bucket = s3.lookup(bucket)
     key_check = bucket.get_key(obj)
-    if key_check:
+    if not key_check:
+        return None
     md5_remote = key_check.etag[1:-1]
     etag_multipart = '-' in md5_remote # Check for multipart, etag is not md5
     if etag_multipart is True: