swapping to internal references

[Gregory-Pereira]

/cc @lance @osmman

[openshift-ci]

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[JasonPowr]

I tested this by

1. Building the Dockerfile and using it in the operator (All good)
2. Ran 'make test' (All Good)

I then tried to run make fulcio and I ran into this error:

protoc --plugin=protoc-gen-go=/home/japower/Projects/go-workspace/src/work/securesign/fulcio/hack/tools/bin/protoc-gen-go \
       --go_opt=module=github.com/securesign/fulcio --go_out=. \
       --plugin=protoc-gen-go-grpc=/home/japower/Projects/go-workspace/src/work/securesign/fulcio/hack/tools/bin/protoc-gen-go-grpc \
       --go-grpc_opt=module=github.com/securesign/fulcio --go-grpc_out=. \
       --plugin=protoc-gen-grpc-gateway=/home/japower/Projects/go-workspace/src/work/securesign/fulcio/hack/tools/bin/protoc-gen-grpc-gateway \
       --grpc-gateway_opt=module=github.com/securesign/fulcio --grpc-gateway_opt=logtostderr=true --grpc-gateway_out=. \
       --plugin=protoc-gen-openapiv2=/home/japower/Projects/go-workspace/src/work/securesign/fulcio/hack/tools/bin/protoc-gen-openapiv2 \
       --openapiv2_out . \
           -I third_party/googleapis/ -I . ./fulcio_legacy.proto ./fulcio.proto
--go_out: github.com/sigstore/fulcio/pkg/generated/protobuf/legacy/fulcio_legacy.pb.go: generated file does not match prefix "github.com/securesign/fulcio"
make: *** [Makefile:59: pkg/generated/protobuf/%.go] Error 1

Changes need to made in the fulcio_legacy.proto and fulcio.proto to reflect the changes :)