Modular Square Root (spurious?) failure for FKM12_447 about constantine

[mratsim]

Minimal reproducing example (with -d:Constantine32):

import  ../constantine/[arithmetic, primitives],
        ../constantine/io/[io_fields],
        ../constantine/config/[curves, common]

var a: Fp[FKM12_447]
a.fromHex("0x406e5e74ee09c84fa0c59f2db3ac814a4937e2f57ecd3c0af4265e04598d643c5b772a6549a2d9b825445c34b8ba100fe8d912e61cfda43d")

a.square()

doAssert: bool a.isSquare()