Tuple constructor incorrectly handles single element values

The Tuple constructor supposedly handled single argument calls as a hint to use the underlying Array as elements.

This behaviour is not correctly implemented as of 4.1.0 (it should be if (elements.length === 1 && util.isArray(elements[0])) instead) but in any case, the behaviour is dangerous as it doesn't allow single element tuple with Arrays to be created.

Tuple.fromArray() should continue to be working as is.