It may just be a matter of tightening the banjo bolt a bit..... But it wouldn't hurt to replace both of the washers. There is one immediately under the head
of the banjo bolt, and another between the injection pump
body and the fuel
Remove the banjo bolt and both washers. Take the bolt and the washers and visit a local diesel
injection pump shop and get a couple or three or four replacements
for each washer. They may or may not be the same on both sides of the fuel
Replace the old with the new and snug things up. You may have to prime up the injection pump a bit, but things will probably crank up fine.
Put the extra washers in your " glory bag" and you're set for next time.