fixed update backdrop errors

diff --git a/SVUI_!Core/system/dock.lua b/SVUI_!Core/system/dock.lua
index c0f4d00..0c5dcef 100644
--- a/SVUI_!Core/system/dock.lua
+++ b/SVUI_!Core/system/dock.lua
@@ -1324,7 +1324,9 @@ local OptionMenu_SliderFunc = function(self, value)
 	if(frame) then
 		local name = frame:GetName();
 		MOD.private.Opacity[name] = value;
-		frame:UpdateBackdrop();
+		if(frame.UpdateBackdrop) then
+			frame:UpdateBackdrop()
+		end
 	end
 end

@@ -1642,7 +1644,9 @@ function MOD:NewDocklet(location, globalName, readableName, texture, onenter)
 	frame.SetVisibilityCallbacks = Docklet_SetVisibilityCallbacks;

 	frame.backdrop = self.SetThemedBackdrop(frame)
-	frame:UpdateBackdrop()
+	if(frame.UpdateBackdrop) then
+		frame:UpdateBackdrop()
+	end
 	frame.resize = CreateFrame("Button", nil, frame);
 	frame.resize:SetSize(16,16)
 	frame.resize:SetPoint("BOTTOMRIGHT", frame, "BOTTOMRIGHT", 0, 0)