[libcalamares] Warn about badly-configured GeoIP

- Warn when type will be none
 - Re-order warnings from general to specific

src/libcalamares/geoip/Handler.cpp

@@ -64,17 +64,21 @@ Handler::Handler( const QString& implementation, const QString& url, const QStri
 {
     bool ok = false;
     m_type = handlerTypes().find( implementation, ok );
+    if ( !ok )
+    {
+        cWarning() << "GeoIP style" << implementation << "is not recognized.";
+    }
+    else if ( m_type == Type::None )
+    {
+        cWarning() << "GeoIP style *none* does not do anything.";
+    }
 #if !defined(QT_XML_LIB)
-    if ( m_type == Type::XML )
+    else if ( m_type == Type::XML )
     {
         m_type = Type::None;
-        cWarning() << "GeoIP style XML is not supported in this version of Calamares.";
+        cWarning() << "GeoIP style *xml* is not supported in this version of Calamares.";
     }
 #endif
-    if ( !ok )
-    {
-        cWarning() << "GeoIP Style" << implementation << "is not recognized.";
-    }
 }
 
 Handler::~Handler()