Core/MMAPS: Fix invisible wall issue in MMAPS.

Fix invisible wall issues in MMAPS caused by tile connections not being extracted correctly.
This reverts aa645683b8b25bfb35cb977678daf5c56c1531e6 and restores an old version of recastnavigation, most likely https://github.com/memononen/recastnavigation/commit/1be9de72d87dcfdecf6bea30f5461745f7d7afe6 .

Re-extracting MMAPS is required.