fix(protobuf): protobuf/build.rs get stuck when patch is already applied

[ldm0]

protobuf/build.rs is occasionally stucked. The reason is that patch requires user input if the patch has already been applied:

$ patch -p1 -i "../../protobuf/src/fix-conformance_test_runner-cmake-build.patch"
patching file 'cmake/conformance.cmake'
Reversed (or previously applied) patch detected!  Assume -R? [y] 

Adding the -f flag solves the issue.

[caspermeijn]

On my machine, the command doesn't get stuck on it when the command is run by cargo. But I do occasionally see that output when another build step fails.

I want to update protobuf to a newer version that doesn't require the patch anymore. I expect that to land in a week.