It was amended in 1908 according to snopes:
"In 1908 the act was amended. The nine-month limit on federal service was deleted; the President would now set the ength of federal service. The ban on Guard units serving outside the United States was dropped. Clearly establishing the Guard's role as the Army's reserve force, the amended act stated that during a mobilization the Guard had to be called before the Army could organize a federal volunteer force."
But nothing was amended as far as the no gun control part of the law. Should still be valid.