Code review comment for lp:~phill-ridout/openlp/bible_media_item_refactors

Issues:

- Text search does not work if "Search while typing" is disabled
- If you do a reference search and enter faulty book name and number,
  the following traceback will appear:

Traceback (most recent call last):
  File "D:\bzr\openlp\bible_media_item_refactors\openlp\plugins\bibles\lib\mediaitem.py", line 612, in on_search_button_clicked
    self.text_search()
  File "D:\bzr\openlp\bible_media_item_refactors\openlp\plugins\bibles\lib\mediaitem.py", line 700, in text_search
    self.text_reference_search(text)
  File "D:\bzr\openlp\bible_media_item_refactors\openlp\plugins\bibles\lib\mediaitem.py", line 643, in text_reference_search
    self.display_results()
  File "D:\bzr\openlp\bible_media_item_refactors\openlp\plugins\bibles\lib\mediaitem.py", line 737, in display_results
    items = self.build_display_results(self.bible, self.second_bible, self.search_results)
  File "D:\bzr\openlp\bible_media_item_refactors\openlp\plugins\bibles\lib\mediaitem.py", line 763, in build_display_results
    for count, verse in enumerate(search_results):
TypeError: 'NoneType' object is not iterable