Allow wizmode illegal teleports only outside of the debug fuzzer

I have had two fuzzer crashes that ended up tracing back to the fuzzer
teleporting directly onto a monster:

 1. a vision blocking mismatch when the hero teleported and displaced a
    mimic imitating a boulder
 2. a "you over monster" sanity check failure when the hero teleported
    onto the same space as a monster in water, drowned (multiple times),
    and the level was full of monsters so there was nowhere to relocate
    them to

Since both of these derive from behavior that is only allowed in wizard
mode (and not allowed at all upstream) anyway, address this narrowly by
simply removing the debug fuzzer's ability to teleport to a specified
destination and actually arrive there no matter what would make it
illegal in normal play. It is still possible to do this (and expose
these impossibles) in normal wizard mode.

Author: copperwater

src/teleport.c

@@ -918,7 +918,10 @@ scrolltele(struct obj *scroll)
         /* possible extensions: introduce a small error if
             magic power is low; allow transfer to solid rock */
         if (teleok(cc.x, cc.y, FALSE)
-            || (wizard
+            /* only allow illegal teleport overriding outside the debug fuzzer
+             * since teleporting directly onto a monster exposes a number of
+             * bugs that are impossible in the absence of teleport overriding */
+            || (wizard && !iflags.debug_fuzzer
                 && y_n("You can't normally teleport here. Do it anyway?")
                     == 'y')) {
             /* for scroll, discover it regardless of destination */