[unity] Immutable Triangles has no effect by default

[HaraldCsaszar]

Reported on the forum here:
https://esotericsoftware.com/forum/d/26850-question-about-the-spine_trianglecheck-/7

When the define SPINE_TRIANGLECHECK is active (the default), immutableTriangles has no effect.

Fix:
Correct the line ~154 in SkeletonRendererInstruction.cs GeometryNotEqual to:

if (a.immutableTriangles != b.immutableTriangles) return true;
if (a.immutableTriangles) return false; // newly added line

and move this block further up, below if (a.hasActiveClipping || b.hasActiveClipping) return true; .
As this is a breaking change, apply this patch in next beta (4.3-beta).

[HaraldCsaszar]

SkeletonRendererInstruction-fix-immutable-2636.zip