[TEST] catch exceptions if TTL already expired when indexing

TTLPercolatorTests indexes docs with small TTLs which can trigger
AlreadyExpiredException exception. This is expected while rare and
we should just catch them.
[TEST] Ignore bogus system properties.

LuceneTestCase might reset some solr properties that cause
our tests to fail if the run before in the same JVM We just ignore
solr properties.