protobuf: 3.7.0 -> 3.7.1

[teto]

Fix fctix mozc issue #60011
I tried to bump moz as well but it failed with various errors, this should be good enough.

          ^
../../unix/fcitx/fcitx_key_event_handler.cc:209:10: error: no template named 'set'; did you mean 'std::set'?
    for (set<commands::KeyEvent::ModifierKey>::const_iterator it =
         ^~~
         std::set
/nix/store/pm4rg0bdiaj5b748kncp9vf7n3x446sd-gcc-7.4.0/include/c++/7.4.0/bits/stl_multiset.h:69:11: note: 'std::set' declared here
    class set;
          ^
13 errors generated.

Motivation for this change

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[teto]

@GrahamcOfBorg build fcitx-engines.mozc

[teto]

care to check this one @Lucus16 ?

[Lucus16]

Upstream introduced a backwards incompatible change in 3.7.0 and reverted it in 3.7.1. It's a patch version bump so there shouldn't be any backwards incompatible changes in this one. Looking at google/mozc#460, It's clear this will fix #60011. I think #59662 should be reverted here. It would also be nice to check fcitx-engines.* and ibus-engines.* automatically whenever their inputs change, but I don't know how to do that.

[teto]

nix-review can rebuild all packages depending on some package but it can be quite resource intensive, which is why I haven't used it here. I use fcitx so I will leave #59662 revert to someone more knowledgeable. I can look at your PR if you create one.