You can turn it into an approximation of an L or even a U by the simple expedient of tying a knot in it.
This is my standard way of dealing with any awkward cable.
It's not perfect, but boy, it's cheap ;-)
From comments - the U-knot is achieved by simply wrapping one end through a second time, if it's not clear from the picture.
BTW - keep the knot very loose, so you don't damage anything.
From further comments -
Of course, no knot is going to help if the cable gets yanked, in any direction; this idea is really just to set the cable off in the direction of the PSU, if that's not to the left of the machine.
Just reducing its tendency to want to be straighter in the 'wrong' direction, nothing more, & reducing pull angularly, rearwards, which is what the older L-plug would do naturally, thereby reducing the lever length of the T-cable in that one direction.