Add --no-audio option

Audio will be enabled by default (when supported). Add an option to
disable it.

Co-authored-by: Romain Vimont <rom@rom1v.com>
Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/options.c

@@ -66,4 +66,5 @@ const struct scrcpy_options scrcpy_options_default = {
     .cleanup = true,
     .start_fps_counter = false,
     .power_on = true,
+    .audio = true,
 };