When this particular medication was quite new a few years ago DVLA were unsure about how safe it was for drivers so they did have special precautions for people using it.
But the rules now just divide medication into three groups as follows:
Medicines (including injectable medicines) which are unlikely to cause hypoglycaemia (unexpected low blood sugar levels).
Medicines that may have a risk of causing hypoglycaemia.
Insulin.
Liraglutide comes into the first category of medicines which are unlikely to cause unexpected hypoglycaemia and therefore there are no special DVLA requirements for monitoring blood sugar levels with this medicine even though it is given by injection, like insulin.