It's a mud guard stay, it's been popped out of the guard about halfway up the picture.
View attachment 525434
It's replaceable for sure, if you can find one.
It might even be repairable with some epoxy.
Will see the poxy method though i doubt it will hold for long on long rides, thats my issue, its plain annoying see the stays hanging out when cycling.
A half decent epoxy will hold it indefinitely, but if you're unsure just unscrew and disconnect it at the fork end... as @Globalti hints at, it's highly doubtful whether it needs two each side. One stay will do fine in the medium, even long term while you source a new mud guard.