[libgdx] Fix json TransformConstraint timeline mixShearY value being ignored. See commit c8f2370.

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/SkeletonJson.java

@@ -821,7 +821,7 @@ public class SkeletonJson extends SkeletonLoader {
 				mixY = mixY2;
 				mixScaleX = mixScaleX2;
 				mixScaleY = mixScaleY2;
-				mixScaleX = mixScaleX2;
+				mixShearY = mixShearY2;
 				keyMap = nextMap;
 			}
 			timelines.add(timeline);