RichTextLabel: On custom effect change, parse bbcode only if it's enabled and not empty.

(cherry picked from commit 9f73abfa9f927ed6109b46991517f824b2ba318e)

scene/gui/rich_text_label.cpp

@@ -2706,7 +2706,9 @@ void RichTextLabel::set_effects(const Vector<Variant> &effects) {
 		custom_effects.push_back(effect);
 	}
 
-	parse_bbcode(bbcode);
+	if ((bbcode != "") && use_bbcode) {
+		parse_bbcode(bbcode);
+	}
 }
 
 Vector<Variant> RichTextLabel::get_effects() {
@@ -2723,7 +2725,9 @@ void RichTextLabel::install_effect(const Variant effect) {
 
 	if (rteffect.is_valid()) {
 		custom_effects.push_back(effect);
-		parse_bbcode(bbcode);
+		if ((bbcode != "") && use_bbcode) {
+			parse_bbcode(bbcode);
+		}
 	}
 }