glm.dvec3 initialized from an array loses precision.

[liufangyuan247]

glm version: 2.7.1

test code:

>>> import glm
>>> data = [1000000.1234, 20000000.1234, 3000000.1234]
>>> a = glm.dvec3(data)
>>> b = glm.dvec3(*data)
>>> a-b
dvec3( 0.0016, -0.1234, -0.1234 )
>>> print(a.x, a.y, a.z)
1000000.125 20000000.0 3000000.0
>>> print(b.x, b.y, b.z)
1000000.1234 20000000.1234 3000000.1234