Fix dungeon wall wrap issue

[fujnw]

See @Aegyo comment for pictorial description of the issue. This is because the game thinks you're trying to access map[10] by wall-wrapping from map[9], and rejects your move right away. It does not give the option to check that map[11] has been visited.

[Ishadijcks]

Can you please add a description to this pr?

[Aegyo]

Step 1: Enter a dungeon and explore the last square of a line

Step 2: Approach the first square of the next line from the right

You are not able to move left from this position.