fix crash on split & reactive settings without view

apps/lib/katemainwindow.cpp

@@ -925,10 +925,6 @@ void KateMainWindow::slotConfigure()
 
 bool KateMainWindow::showPluginConfigPage(KTextEditor::Plugin *configpageinterface, int id)
 {
-    if (!m_viewManager->activeView()) {
-        return false;
-    }
-
     KateConfigDialog *dlg = new KateConfigDialog(this);
     if (configpageinterface) {
         dlg->showAppPluginPage(configpageinterface, id);

apps/lib/kateviewmanager.cpp

@@ -1024,10 +1024,12 @@ void KateViewManager::splitViewSpace(KateViewSpace *vs, // = 0
     vsNew->setActive(true);
     vsNew->show();
 
-    createView(activeView()->document());
+    if (auto v = vs->currentView()) {
+        createView(v->document());
 
-    if (moveDocument) {
-        vs->closeDocument(vs->currentView()->document());
+        if (moveDocument) {
+            vs->closeDocument(v->document());
+        }
     }
 
     updateViewSpaceActions();