Bug#777844: etsf-io: ftbfs with GCC-5

[Antti Järvinen]

I'm fortran-illiterate but by digging through commands used by
./configure in sid I was finally able to extract understandable error
message, saying

>   use netcdf
>      1
>Fatal Error: Cannot read module file 'netcdf.mod' opened at (1), because it was created by a different version of GNU Fortran
>compilation terminated.

By obtaining source of netcfg, compiling and installing that in SID
made this package to successfully build too so this package is not
errorneus and listed in
https://release.debian.org/transitions/html/auto-netcdf.html for a
reason.

--
Antti Järvinen