Fix drunken error for decrease_audio_delay

The lack of the two \\ caused the decrease_audio_delay not to work.

resources/inputmaps/keyboard.json

@@ -29,7 +29,7 @@
     "Ctrl\\+L": "cycle_subtitles_back",
     "S": "toggle_subtitles",
     "Alt\\+A": "increase_audio_delay",
-    "Alt+Shift\\+A": "decrease_audio_delay",
+    "Alt\\+Shift\\+A": "decrease_audio_delay",
     "Alt\\+S": "increase_subtitles_delay",
     "Alt\\+Shift\\+S": "decrease_subtitles_delay",