[Bug-apl] Error in error message INDEX ERROR

[Elias Mårtenson]

When displaying an index error, the error message doesn't take ⎕IO into
account.

To reproduce:

*      x ← ⍳10*
*      x[0]*
INDEX ERROR+
      x[0]
      ^^
*      )more*
⎕IO=1 offending index=-1 max index=10

The offending index should be 0 here.

Regards,
Elias