git archive --remote should generate tar.gz format indicated by -o filename

git archive -o name.tar.gz generates a gzipped file without needing an explicit --format switch.

However, git archive -o name.tar.gz --remote [url] generates a tar file, which is unexpected, bandwidth-heavier, and additionally in some cases it's not immediately obvious that this has happened.

git archive -o name.tar.gz --remote [url] --format tar.gz generates a gzipped file, so there's obviously no limitation with e.g. git-upload- archive.

Given the above, either git archive or git-upload-archive should apply the same tar.gz filename heuristic and generate the expected format.

Presumably e.g. tar.xz support when using --remote would be more problematic since, in the local case, it involves specifying an arbitrary command.