LibWeb: Don't scale by x, x when a scale x, y is provided as a transform

Author: https://github.com/Hendiadyoin1
Commit: https://github.com/SerenityOS/serenity/commit/e68309144b
Pull-request: https://github.com/SerenityOS/serenity/pull/15403

Userland/Libraries/LibWeb/Painting/StackingContext.cpp

@@ -240,7 +240,7 @@ Gfx::FloatMatrix4x4 StackingContext::get_transformation_matrix(CSS::Transformati
                 0, 0, 0, 1);
         if (count == 2)
             return Gfx::FloatMatrix4x4(value(0), 0, 0, 0,
-                0, value(0), 0, 0,
+                0, value(1), 0, 0,
                 0, 0, 1, 0,
                 0, 0, 0, 1);
         break;