It's not a high pressure oil line or it would be a banjo type union, if it really bothers you you could try pulling it out cleaning it up & the hole then refiting it with a smear of loctite 638 high strength retainer preferably but you could use some j.b weld or araldite or even some silcone sealent (just not sure how long the last one would last). but I have used it successfully on race engines in all sort's of places & it's been very reliable .
The loctite can be quite expensive (but I use it at work every day), araldite is also very good on engines as long as you make sure the area is spotlessly clean ,
B.T.B.H, it dosn't look that wet with oil I'd be tempted to just leave well alone.
All the best DDD.
2002 110 HDi estate, Rapier in monaco blue! ( found quite a bit more power ) SOLD I've sorted the airbag light
1998 3.0 V6 SE coupe in Diablo Red ( my baby ) sold
2006 206 1.4 16v sport in Aegean blue ( wife's shopping trolley )