quit uimanager before run uimanager in test

spec/unit/readerui_spec.lua

@@ -7,9 +7,12 @@ local DEBUG = require("dbg")
 
 describe("Readerui module", function()
     local sample_epub = "spec/front/unit/data/leaves.epub"
-    local readerui = ReaderUI:new{
-        document = DocumentRegistry:openDocument(sample_epub),
-    }
+    local readerui
+    setup(function()
+        readerui = ReaderUI:new{
+            document = DocumentRegistry:openDocument(sample_epub),
+        }
+    end)
     it("should save settings", function()
         -- remove history settings and sidecar settings
         DocSettings:open(sample_epub):clear()
@@ -23,6 +26,7 @@ describe("Readerui module", function()
                 readerui.doc_settings.data.last_xpointer)
     end)
     it("should show reader", function()
+        UIManager:quit()
         UIManager:show(readerui)
         UIManager:scheduleIn(1, function() UIManager:close(readerui) end)
         UIManager:run()