Exercise.getAllByCustomerId fix, HTTP test

src/main/kotlin/com/aitrainer/api/service/ExerciseService.kt

@@ -5,6 +5,6 @@ import org.springframework.data.jpa.repository.Query
 import org.springframework.data.repository.query.Param
 
 interface ExerciseService {
-    @Query("FROM Exercises WHERE customer_id = :customerId")
-    fun findAllByCustomerId( @Param("customerId") customerId: Long): List<Exercises>
+    @Query("FROM exercises WHERE customer_id = :customerId")
+    fun findAllByCustomerId( @Param("customerId") customerId: Long? ): List<Exercises>
 }