Removed unused variable from build script.
Removed unused variable from build script.

GoogleCloudPlatform/woolaroo-language-learning-app,GoogleCloudPlatform/woolaroo-language-learning-app,GoogleCloudPlatform/woolaroo-language-learning-app,GoogleCloudPlatform/woolaroo-language-learning-app,GoogleCloudPlatform/woolaroo-language-learning-app