fix mfact not applying to addmaster (#1715)

Co-authored-by: Hill <hillyu@live.com>

src/layout/MasterLayout.cpp

@@ -123,6 +123,7 @@ void CHyprMasterLayout::onWindowCreatedTiling(CWindow* pWindow) {
         }
     } else {
         PNODE->isMaster   = false;
+        PNODE->percMaster = lastSplitPercent;
 
         // first, check if it isn't too big.
         if (const auto MAXSIZE = g_pXWaylandManager->getMaxSizeForWindow(pWindow);