SRC: default to fastest SinC

It is good enough for normal people with only half the CPU usage of
medium quality SinC.
(cherry picked from commit c07d0c4c)

modules/audio_filter/resampler/src.c

@@ -50,7 +50,7 @@ vlc_module_begin ()
     set_description (N_("Secret Rabbit Code (libsamplerate) resampler") )
     set_category (CAT_AUDIO)
     set_subcategory (SUBCAT_AUDIO_MISC)
-    add_integer ("src-converter-type", SRC_SINC_MEDIUM_QUALITY,
+    add_integer ("src-converter-type", SRC_SINC_FASTEST,
                  SRC_CONV_TYPE_TEXT, SRC_CONV_TYPE_LONGTEXT, true)
         change_integer_list (conv_type_values, conv_type_texts)
     set_capability ("audio filter", 60)