Add some codes, returnes directly if the value is not changed.

Avoid executing the following value-changed logics if the value does not really change.

scene/gui/nine_patch_rect.cpp

@@ -105,6 +105,11 @@ Ref<Texture2D> NinePatchRect::get_texture() const {
 
 void NinePatchRect::set_patch_margin(Side p_side, int p_size) {
 	ERR_FAIL_INDEX((int)p_side, 4);
+
+	if (margin[p_side] == p_size) {
+		return;
+	}
+
 	margin[p_side] = p_size;
 	update();
 	update_minimum_size();
@@ -130,6 +135,10 @@ Rect2 NinePatchRect::get_region_rect() const {
 }
 
 void NinePatchRect::set_draw_center(bool p_enabled) {
+	if (draw_center == p_enabled) {
+		return;
+	}
+
 	draw_center = p_enabled;
 	update();
 }
@@ -139,6 +148,10 @@ bool NinePatchRect::is_draw_center_enabled() const {
 }
 
 void NinePatchRect::set_h_axis_stretch_mode(AxisStretchMode p_mode) {
+	if (axis_h == p_mode) {
+		return;
+	}
+
 	axis_h = p_mode;
 	update();
 }
@@ -148,6 +161,10 @@ NinePatchRect::AxisStretchMode NinePatchRect::get_h_axis_stretch_mode() const {
 }
 
 void NinePatchRect::set_v_axis_stretch_mode(AxisStretchMode p_mode) {
+	if (axis_v == p_mode) {
+		return;
+	}
+
 	axis_v = p_mode;
 	update();
 }