[Wien] aim: not work for MgO

[Rong Yu]

Dear WIEN users,

I tried "aim" for search for critical points of different crystals and
found that:

For TiC, it works and can give expected CPs (at least with the keyword
"TWO", not work with "THRE" and "ALL").

But for MgO, NaCl (same structure as TiC), "Segmentation error"
appeared. For all the cases, LM of 10 and GMAX of 20 or more were used. 

I used the latest version. I also tried the prebuilt binary but the
result was the same. 

Thanks for you help.

Rong