Unless you have very tall skirting boards, the sockets are likely to not comply to modern regulations in respect of how high from the floor they are. It's a sign the wiring is old and it may need to be replaced. We live an old house and there are a few places where there have been sockets in the skirting boards in the past. We had some work done last year and the electrician found rubber insulated cables where the rubber had perished so a lot of rewiring was done.
All of our sockets were in the skirting boards (house was built in 1860s). We replaced all the skirting boards as we had a new wooden floor put down so took the opportunity to move the sockets up. It was a rats nest of wiring so glad we did.
I wouldn't worry about trying to meet the current regs unless the cabling is old and your having to completely rewire anyway. It's not a requirement for old building to meet current regs unless you are doing major alterations that need a building warrant, even at that certain things will receive exceptions based on it being an old house.
The height for sockets and light switches have been changed for disabled access reasons (able to use them from a wheelchair), theres nothing unsafe about them being on the skirting.