Fix null handling

Author: k163377

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinValueInstantiator.kt

@@ -35,7 +35,7 @@ internal class KotlinValueInstantiator(
     private fun List<KTypeProjection>.markedNonNullAt(index: Int) = getOrNull(index)?.type?.isMarkedNullable == false
 
     private fun SettableBeanProperty.skipNulls(): Boolean =
-        nullIsSameAsDefault || (getAnnotation(JsonSetter::class.java).nulls == Nulls.SKIP)
+        nullIsSameAsDefault || (getAnnotation(JsonSetter::class.java)?.nulls == Nulls.SKIP)
 
     override fun createFromObjectWith(
         ctxt: DeserializationContext,