man: update description of ask_before_clearing_playlists

doc/ncmpcpp.1

@@ -270,8 +270,8 @@ If enabled, ncmpcpp will ask for % of locked screen's width each time you want t
 .B jump_to_now_playing_song_at_start = yes/no
 If enabled, ncmpcpp will jump at start to now playing song if mpd is playing or paused.
 .TP 
-.B ask_before_clearing_main_playlist = yes/no
-If enabled, user will be asked if he really wants to clear the main playlist after pressing key responsible for that.
+.B ask_before_clearing_playlists = yes/no
+If enabled, user will be asked if he really wants to clear the playlist after pressing key responsible for that.
 .TP 
 .B clock_display_seconds = yes/no
 If enabled, clock will display time in format hh:mm:ss, otherwise hh:mm.