Fix transform center2d for 2d views

While this didn't show up as a bug, the center2d was being calculated with a zero aspect,
causing TransInfo.center2d to be NAN.

source/blender/editors/transform/transform_generics.c

@@ -1421,8 +1421,8 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 	}
 #endif
 
-	setTransformViewMatrices(t);
 	setTransformViewAspect(t, t->aspect);
+	setTransformViewMatrices(t);
 	initNumInput(&t->num);
 }
 
@@ -1582,6 +1582,8 @@ void restoreTransObjects(TransInfo *t)
 
 void calculateCenter2D(TransInfo *t)
 {
+	BLI_assert(!is_zero_v3(t->aspect));
+
 	if (t->flag & (T_EDIT | T_POSE)) {
 		Object *ob = t->obedit ? t->obedit : t->poseobj;
 		float vec[3];