FIX additional exception handling for Tika errors return via Guzzle.

Tika server errors via Guzzle can cause the Solr search query to return a 500 error and breaks search results pages for users. Issue was relating to uncaught exceptions from Guzzle causing a silent fail if a text file is perhaps unreadable or missing (return null never occurs which breaks the search). 

Please check patch over and test on other server OS's, this fixed a major error when running this module on SLE11 SP2.