Exclude dependency on tika-parsers 1.x

In Magnolia 6.2.23 tika libraries were updated (BUILD-684) However, magnolia-content-indexer is still using the old tika version, which ends up in conflict.

tika dependency should be updated in magnolia-content-indexer accordingly.

Dev Notes:

Due to an issue with one release of Magnolia's own crawler4j fork (3rd party library no longer maintained by its authors), it is recommended to use version 6.1.2 instead of 6.1.1. 

Solr 6.1.2 is already available on Nexus.