Merge pull request #906 from k163377/fix-prop

Delete Javadoc for deleted property

Author: k163377

src/main/kotlin/tools/jackson/module/kotlin/KotlinModule.kt

@@ -19,8 +19,6 @@ fun Class<*>.isKotlinClass(): Boolean = this.isAnnotationPresent(Metadata::class
  *  using the default value provided in Kotlin.
  * @property singletonSupport        Default: false.  Mode for singleton handling.
  *  See [KotlinFeature.SingletonSupport]
- * @property enabledSingletonSupport Default: false.  A temporary property that is maintained until the return value of `singletonSupport` is changed.
- *  It will be removed in 2.21.
  * @property strictNullChecks        Default: false.  Whether to check deserialized collections.  With this disabled,
  *  the default, collections which are typed to disallow null members
  *  (e.g. List<String>) may contain null values after deserialization.  Enabling it