Add known issue.

wiki/src/support/known_issues.mdwn

@@ -175,3 +175,12 @@ Since 0.17.1, VirtualBox guest modules are no shipped anymore.
 See [[!tails_todo fix_virtualbox_guest_modules_build desc="the
 corresponding task"]] for details.
 
+The default web search engine is not the intended one
+-----------------------------------------------------
+
+The web browser default search engine is Google, instead of the
+intended localized Startpage. You may select *Startpage HTTPS* in the
+search engine menu next to the Google icon.
+
+See [[!tails_todo fix_localized_iceweasel_search_engine desc="the
+corresponding task"]] for details.

wiki/src/todo/fix_localized_iceweasel_search_engine.mdwn

@@ -3,7 +3,8 @@ Google configured as the default search engine. No localized Startpage
 is available. "Startpage HTTPS" is available. Only English Wikipedia
 is available.
 
-Same at least for Spanish and French. Added to 0.18's known issues.
+Same at least for Spanish and French. Added to 0.18's and longstanding
+known issues.
 
 [[!tag todo/research]]