Fix warning for unused ustatus.proto (#186)

Once I committed #173 I caused an issue with a warning that appears that ustatus proto is included in uattributes.proto even though it is not used so this issue will be used to remove the warning.

#185

Author: Steven Hartley

up-core-api/uprotocol/v1/uattributes.proto

@@ -17,7 +17,6 @@ package uprotocol.v1;
 
 import "uprotocol/v1/uri.proto";
 import "uprotocol/v1/uuid.proto";
-import "uprotocol/v1/ustatus.proto";
 import "uprotocol/v1/ucode.proto";
 import "uprotocol/uoptions.proto";