Suppress warning in waitstream_core().

Suppress the warning about unexpected control subclass frames for
AST_CONTROL_CONNECTED_LINE, AST_CONTROL_REDIRECTING, and AST_CONTROL_AOC
in file.c:waitstream_core().


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@268578 65c4cc65-6c06-0410-ace0-fbb531ad65f3