Avoid NPE when going from search to another page

java.lang.NullPointerException
at org.wikipedia.Utils.hideSoftKeyboard(Utils.java:171)
at org.wikipedia.search.SearchArticlesFragment.navigateToTitle(SearchArticlesFragment.java:481)
at org.wikipedia.search.SearchArticlesFragment.navigateToTitle(SearchArticlesFragment.java:476)

Change-Id: I763a4b1c2f4acbc257930eab97206843478f10e3
Merge "Avoid NPE when going from search to another page"