Fixed #1030

What have you done in this MR?

• Fixed quest lock. (When a player run from GardenerNPC too far, where after returning, digging out the chest was impossible which made it unable to complete.)

• If you want test:

0. Use in-game command: ::setqueststage 23 20,
1. Use in-game command: ::item 433 to get Pirate message (and read it),
2. again ::item 952 to get the spade,
3. Dig at point 1 But I think the grid is one square further to the right (according to map below), After gardener appear, run away far than 16 tiles,
4. Back and use spade again to complete the quest.

Are there any tricky things testers should keep an eye out for?

• No but i'm not sure.

• I have tested these changes thoroughly.

• I acknowledge that this contribution will be released under the AGPL license.