run-tests: fix crash when --json and --blacklist are both used (issue5050)...
run-tests: fix crash when --json and --blacklist are both used (issue5050)
This patch fixes a crash when both --json and --blacklist were given as
arguments of run-tests.py. Now, instead of crashing, we add an entry for
blacklisted tests in the json output to show that the tests were skipped.