Allow all weather screens to be deleted

This resolves an issue where it was impossible to delete all screens. This
was especially problematic when those screens were attached to
grabbers which no longer existed.

mythplugins/mythweather/mythweather/weather.cpp

@@ -151,6 +151,7 @@ bool Weather::SetupScreens()
     {
         if (m_firstSetup)
         {
+            m_firstSetup = false;
             // If no screens exist, run the setup
             MythScreenStack *mainStack = GetMythMainWindow()->GetMainStack();
 
@@ -167,8 +168,6 @@ bool Weather::SetupScreens()
             {
                 delete ssetup;
             }
-
-            m_firstSetup = false;
         }
         else
         {

mythplugins/mythweather/mythweather/weatherSetup.cpp

@@ -392,13 +392,6 @@ void ScreenSetup::loadData()
 
 void ScreenSetup::saveData()
 {
-    if (m_activeList->GetCount() <= 0)
-    {
-        LOG(VB_GENERAL, LOG_ERR,
-            "No Active Screens are defined. Nothing Saved.");
-        return;
-    }
-
     // check if all active screens have sources/locations defined
     QStringList notDefined;