app_chanspy: fix audiohook options in non read-only mode

When option 'o' was not set, ChanSpy created its audiohook with the flag
AST_AUDIOHOOK_MUTE_WRITE, which caused ChanSpy to listen audio from one
direction only.

ASTERISK-25866 #close

Change-Id: I5c745855eea29a3fbc4e4aed0b0c0f53580535e0