By Susanna Twidale and Nora Buli LONDON/OSLO (Reuters) – Europe’s plans to build stocks and ensure gas supplies for next winter could be upended if exports from Russia are halted in a standoff over payment terms, risking curbs on industrial use, analysts warned. Russia typically provides Europe with around 40% of its gas but the possibility of supply disruption since Moscow’s invasion of Ukraine has increased over the past week, with G7 nations rejecting a demand for payment in roubles. The European Commission says gas held in storage typically accounts for around a quarter of that used in Eur…