Changes

rcptt: Use https for tracecompass-test-traces dependency

The RCPTT execution fails in Eclipse Trace Compass's CI environment:

"maven-default-http-blocker: Blocked mirror for repositories ..."

Using https instead of http should fix that.

Change-Id: I75a1ea580ad83e2b9771d03ea5f245426460fc09
Signed-off-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/193763
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>