font.cpp does not need gettext,

...and we can move it to wesnoth-lib where it belongs without problem,
since it has no translatable strings yet

po/wesnoth-lib/POTFILES.in

@@ -1,4 +1,5 @@
 src/filechooser.cpp
+src/font.cpp
 src/hotkeys.cpp
 src/mapgen_dialog.cpp
 src/marked-up_text.cpp 

po/wesnoth/POTFILES.in

@@ -2,7 +2,6 @@ src/about.cpp
 src/actions.cpp
 src/dialogs.cpp
 src/display.cpp
-src/font.cpp
 src/game.cpp
 src/game_events.cpp
 src/help.cpp

src/font.cpp

@@ -16,10 +16,9 @@
 #include "global.hpp"
 
 #include "config.hpp"
-#include "font.hpp"
 #include "filesystem.hpp"
+#include "font.hpp"
 #include "game_config.hpp"
-#include "gettext.hpp"
 #include "log.hpp"
 #include "sdl_utils.hpp"
 #include "tooltips.hpp"