By Caleb Davis GDANSK (Reuters) -One-way flights out of Russia were rocketing in price and selling out fast on Wednesday after President Vladimir Putin ordered the immediate call-up of 300,000 reservists. Putin’s announcement, made in an early-morning television address, raised fears that some men of fighting age would not be allowed to leave the country. Defence Minister Sergei Shoigu said the call-up would be limited to those with experience as professional soldiers, and that students and conscripts would not be called up. The Kremlin declined to comment on whether the borders would be close…