Acoustic sum rule broken when NONANALYTIC=3

[ttadano]

At the gamma point, the dynamical matrix must satisfy the acoustic sum rule (ASR). However, when NONANALYTIC=3 is set, the ASR is broken even when the Born effective charges are symmetrized. This occurs only when the Born effective charges have non-zero off-diagonal elements. The effect of this ASR breaking seems to be minor, but this bug(?) should be solved.