Revert "Tell ogr2ogr not to create spatial indices. We do that."

This reverts commit dd5245e073799d1dd8861e15bbc4fcf23ccc3378.

Found to be bogus:
ogr2ogr output: -nlt PROMOTE_TO_MULTISPATIAL_INDEX=OFF: type not recognised.

CDB-1722 #comment if anyone wants to play with this...