master: avoid crash if openingon null in onWindowCreated

Author: vaxerski

src/layout/MasterLayout.cpp

@@ -179,7 +179,7 @@ void CHyprMasterLayout::onWindowCreatedTiling(PHLWINDOW pWindow, eDirection dire
 
     if ((BNEWISMASTER && g_pInputManager->m_dragMode != MBIND_MOVE)                //
         || WINDOWSONWORKSPACE == 1                                                 //
-        || (WINDOWSONWORKSPACE > 2 && !pWindow->m_firstMap && OPENINGON->isMaster) //
+        || (WINDOWSONWORKSPACE > 2 && !pWindow->m_firstMap && OPENINGON && OPENINGON->isMaster) //
         || forceDropAsMaster                                                       //
         || (*PNEWSTATUS == "inherit" && OPENINGON && OPENINGON->isMaster && g_pInputManager->m_dragMode != MBIND_MOVE)) {