4.1 compile failure: i.ortho.photo

[Greg Koerper]

Here's what seems to be the fix:

[in src.alpha/imagery/i.ortho.photo/photo.2image/zoom_box.c, but ALSO
 in src.alpha/imagery/i.ortho.photo/photo.2target/zoom_box.c AS WELL]

static
zoom1(x,y)  /* called by Input_pointer */
{
    static int use = 1;
    int cancel();       /* added 930512 after compile failure */
    int zoom2();

Just add the declaration of cancel().  Well, it compiles--isn't that 
evidence enough?

greg