Replaced double-quotes with single quotes

Author: dennis

tools/ports/sdl2_mixer.py

@@ -10,9 +10,9 @@
 
 deps = ['sdl2']
 variants = {
-  'sdl2_mixer-mp3': {'SDL2_MIXER_FORMATS': ["mp3"]},
+  'sdl2_mixer-mp3': {'SDL2_MIXER_FORMATS': ['mp3']},
   'sdl2_mixer-none': {'SDL2_MIXER_FORMATS': []},
-  'sdl2_mixer-mp3-mt': {'SDL2_MIXER_FORMATS': ["mp3"], 'PTHREADS': 1},
+  'sdl2_mixer-mp3-mt': {'SDL2_MIXER_FORMATS': ['mp3'], 'PTHREADS': 1},
   'sdl2_mixer-none-mt': {'SDL2_MIXER_FORMATS': [], 'PTHREADS': 1},
 }