Bug 1305794 - Remove Cortana-related strings from mozilla-central. r=felipe

Original patch by Filipe, and patch clean-up by Thomas Charles <thomascharles94@hotmail.co.uk>

MozReview-Commit-ID: H9C2C6gk40v

browser/locales/en-US/chrome/browser/preferences/search.dtd

@@ -13,9 +13,6 @@
 <!ENTITY showURLBarSuggestions.accesskey       "l">
 <!ENTITY urlBarSuggestionsPermanentPB.label    "Search suggestions will not be shown in location bar results because you have configured &brandShortName; to never remember history.">
 
-<!ENTITY redirectWindowsSearch.label "Use this search engine for searches from Windows">
-<!ENTITY redirectWindowsSearch.accesskey "W">
-
 <!ENTITY oneClickSearchEngines.label           "One-click search engines">
 
 <!ENTITY chooseWhichOneToDisplay.label         "The search bar lets you search alternate engines directly. Choose which ones to display.">