NullPointerException when GWC disk quota monitoring is disabled
Description
When disabling the disk quota monitoring (environment variable GWC_DISKQUOTA_DISABLED set to true) there is a NullPointerException in the logs on shut down:
WARN 1 --- [ionShutdownHook] o.s.b.f.support.DisposableBeanAdapter : Invocation of destroy method failed on bean with name 'DiskQuotaStoreProvider': java.lang.NullPointerException: Cannot invoke "org.geowebcache.diskquota.QuotaStore.close()" because "this.store" is null
When disabling the disk quota monitoring (environment variable GWC_DISKQUOTA_DISABLED set to true) there is a NullPointerException in the logs on shut down:
WARN 1 --- [ionShutdownHook] o.s.b.f.support.DisposableBeanAdapter : Invocation of destroy method failed on bean with name 'DiskQuotaStoreProvider': java.lang.NullPointerException: Cannot invoke "org.geowebcache.diskquota.QuotaStore.close()" because "this.store" is null