main_notify: make the read side of the pipe blocking

Currently, both sides of the pipe are blocking, although we do not
need blocking read().  Convert it back to blocking.  Eliminate the
select() from wait_main_task().

src/utils.h

@@ -95,8 +95,6 @@ char *parsePath(char *path);
 
 int set_nonblocking(int fd);
 
-void init_async_pipe(int file_des[2]);
-
 int stringFoundInStringArray(const char *const*array, const char *suffix);
 
 #endif