launchpad: fix dynamic adaption of chunck size

[bdrung]

The chunk size in HTTPSProgressConnection.send starts with 1024. The chunk size is checked for being bigger than 1024 before increasing or decreasing it. Therefore this condition will never met and the chunk size will stay at 1024.

Only check for the chunk size to be bigger than 1024 before decreasing it (not before increasing it).

I ran the integration tests locally, but HTTPSProgressConnection is not covered by it:

TEST_LAUNCHPAD=1 pytest -ra --cov=. --cov-report=html --cov-branch tests/integration/test_crashdb_launchpad.py