also build translation files (*.mo)

Index: Makefile
--- Makefile.orig
+++ Makefile
@@ -37,6 +37,7 @@ PROJECT_VERSION := $(file < version.txt)
 
 all:
 	$(MAKE) -C src
+	$(MAKE) -C files/lang
 ifndef FHEROES2_MACOS_APP_BUNDLE
 	@cp src/dist/$(TARGET) .
 endif
