science/berkeleygw: Unbreak build with GCC 10

epsilon_main.f90:1271:72:

1271 | call epsinv(gvec,pol,ekin,qq,is_q0,crys,scal,kp,omega_plasma,iq)

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Error: Missing actual argument for argument '_formal_18' at (1)

http://package18.nyi.freebsd.org/data/121amd64-default-PR244494/2020-06-10_18h04m44s/logs/errors/BerkeleyGW-2.0.0_5.log

PR: 246700