By City A.M. Editorial Avoiding self-help gurus in January is akin to dodging potholes on London’s roads: very difficult indeed. Now that every marketing consultant in Britain is also a LinkedIn influencer, it’s becoming even more challenging to avoid ever-more facile drivel about looking forward, turning the page, and living, laughing and loving your way into 2024. One person who has somehow avoided this peurile nonsense is the Mayor of London, who tonight will deliver a speech bemoaning the Brexit vote, now eight years ago. One can only assume that rather than the new year, new you rubbish t…