CURA-5164 Fix typo in the method signature

cura/CuraApplication.py

@@ -406,8 +406,8 @@ class CuraApplication(QtApplication):
         )
 
     # Runs preparations that needs to be done before the starting process.
-    def startSlashWindowPhase(self):
-        super().startSlashWindowPhase()
+    def startSplashWindowPhase(self):
+        super().startSplashWindowPhase()
 
         self.setWindowIcon(QIcon(Resources.getPath(Resources.Images, "cura-icon.png")))
 

cura_app.py

@@ -125,7 +125,7 @@ app.addCommandLineOptions()
 app.parseCliOptions()
 app.initialize()
 
-app.startSlashWindowPhase()
-app.startPostSlashWindowPhase()
+app.startSplashWindowPhase()
+app.startPostSplashWindowPhase()
 
 app.run()