Remove "hasAdditionalColour2" from wmmine

Author: ZeeMaji

objects/rct2/ride/rct2.ride.wmmine.json

@@ -61,7 +61,6 @@
                     "gentleSlopes": true,
                     "steepSlopes": true
                 },
-                "hasAdditionalColour2": true,
                 "hasSwinging": true,
                 "hasScreamingRiders": true,
                 "useWoodenWildMouseSwing": true,