Oak run indexing silently broken without tika.jar (text rendition)

If "java oak-run.jar createIndex ..." is used without the tika.jar or its dependencies, then text extraction is not made (for those binaries where the parser is missing in the classpath). This is silent: there is no warning or exception.

It would be better if oak-run createIndex prevents indexing if tika / its dependencies are missing. An override is needed.