Fix #34956: rendering animation with audio would crash with an older ffmpeg
after recent changes.

New ffmpeg versions accept align = 0 as a parameter and will set it to 1
automatically, but older ones need to pass align = 1.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55969 954f8c5b-7b00-dc11-b283-0030488c597c