In https://git.eclipse.org/r/c/144009/ UploadPack tests moved from
thrown to assertThrows, but newly introduced tests are still using
the thrown.
Update test so all of them use assertThrows.
Change-Id: I0ff19a6f8ba9e978d8ffc7a912c0572d9f00c7fa
Signed-off-by: Ivan Frade <ifrade@google.com>