remove defautl setting on tty when exec

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>

src/parse.c

@@ -1063,7 +1063,6 @@ realloc:
 		goto out;
 	}
 
-	exec->tty = 1;
 	exec->ptyfd = -1;
 	exec->stdinfd = -1;
 	exec->stdoutfd = -1;