Added information about config option to NEWS

Author: Enzime

vimperator/NEWS

@@ -1,5 +1,9 @@
 201x-xx-xx:
     * Stop propagation for keyboard event if that key are contained in -except option on :ignorekeys
+    * Closing the last tab of a window now respects the Firefox setting:
+    browser.tabs.closeWindowWithLastTab, which means those who are used to :tabclose never closing
+    the window when closing the last tab, should set this option to false (either through about:config
+    or with :set! browser.tabs.closeWindowWithLastTab=false)
 
 2015-08-25:
     * Version 3.10.1