Fix typo. Close #1865

src/libvlc-module.c

@@ -624,7 +624,7 @@ static const char *const ppsz_clock_descriptions[] =
 #define INPUT_SUBTRACK_LANG_TEXT N_("Subtitle language")
 #define INPUT_SUBTRACK_LANG_LONGTEXT N_( \
     "Language of the subtitle track you want to use " \
-    "(comma separated, two or tree letter country code).")
+    "(comma separated, two or three letters country code).")
 
 /// \todo Document how to find it
 #define INPUT_AUDIOTRACK_ID_TEXT N_("Audio track ID")