Google introduced a new protobuf API: https://blog.golang.org/protobuf-apiv2 causing the current release of staticckeck to barf on several related packages: dominikh/go-tools#732 ... fixed in dominikh/go-tools@7e758a3

Currently, protoc-gen-microweb uses `github.com/golang/protobuf/jsonpb` which is still reported:
```
make staticcheck
go run honnef.co/go/tools/cmd/staticcheck -tags '' github.com/owncloud/ocis-hello/cmd/ocis-hello github.com/owncloud/ocis-hello/pkg/assets github.com/owncloud/ocis-hello/pkg/command github.com/owncloud/ocis-hello/pkg/config github.com/owncloud/ocis-hello/pkg/flagset github.com/owncloud/ocis-hello/pkg/metrics github.com/owncloud/ocis-hello/pkg/proto/v0 github.com/owncloud/ocis-hello/pkg/server/debug github.com/owncloud/ocis-hello/pkg/server/grpc github.com/owncloud/ocis-hello/pkg/server/http github.com/owncloud/ocis-hello/pkg/service/v0 github.com/owncloud/ocis-hello/pkg/version
pkg/proto/v0/hello.pb.micro.go:8:2: package github.com/golang/protobuf/proto is deprecated: Use the "google.golang.org/protobuf/proto" package instead.  (SA1019)
pkg/proto/v0/hello.pb.web.go:14:2: package github.com/golang/protobuf/jsonpb is deprecated: Use the "google.golang.org/protobuf/encoding/protojson" package instead.  (SA1019)
exit status 1
make: *** [Makefile:73: staticcheck] Fehler 1
```

This PR should update the dependency.