openshift-java-client: don't refresh env variables on each addition/removal

		EnvironmentVariableResourceDTO environmentVariableResourceDTO =
				new AddEnvironmentVariableRequest().execute(name, value);
		IEnvironmentVariable environmentVariable = new EnvironmentVariableResource(environmentVariableResourceDTO, this);
		updateEnvironmentVariables();
		return environmentVariable;

	protected void updateEnvironmentVariables() throws OpenShiftException {
		if (environmentVariableByName == null) {
			environmentVariableByName = loadEnvironmentVariables();
		} else {
			environmentVariableByName.clear();
			environmentVariableByName.putAll(loadEnvironmentVariables());
		}
	}