Make Line2D be white by default

scene/2d/line_2d.cpp

@@ -43,7 +43,7 @@ Line2D::Line2D() {
 	_begin_cap_mode = LINE_CAP_NONE;
 	_end_cap_mode = LINE_CAP_NONE;
 	_width = 10;
-	_default_color = Color(0.4, 0.5, 1);
+	_default_color = Color(1, 1, 1);
 	_texture_mode = LINE_TEXTURE_NONE;
 	_sharp_limit = 2.f;
 	_round_precision = 8;