Remove redundant secp256k1_fe_normalize from secp256k1_gej_add_ge_var.

This was a missed optimization in the extraction of gej+ge from gej+gej.
Merge pull request #139

1c29f2e Remove redundant secp256k1_fe_normalize from secp256k1_gej_add_ge_var. (Gregory Maxwell)
Another redundant secp256k1_fe_normalize
Variable time normalize