Crash when adding a file after device removal
********** Crash dump: **********
Build fingerprint: 'BouyguesTelecom/Bouygtel4K/HMB9213NW:6.0.1/ALASKA/4.60.67:user/release-keys'
pid: 4125, tid: 4308, name: AndroidMedialib >>> org.videolan.vlc.debug <<<
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0
Stack frame #00 pc 000da8b6 /data/app/org.videolan.vlc.debug-2/lib/arm/libmla.so (_ZNK12medialibrary6parser16MetadataAnalyzer18createFileAndMediaERNS0_5IItemE+577): Routine medialibrary::parser::MetadataAnalyzer::createFileAndMedia(medialibrary::parser::IItem&) const at /mnt/ssd/vlc-android/medialibrary/medialibrary/build-android-armeabi-v7a/../src/metadata_services/MetadataParser.cpp:407
Stack frame #01 pc 000d8f11 /data/app/org.videolan.vlc.debug-2/lib/arm/libmla.so (_ZN12medialibrary6parser16MetadataAnalyzer3runERNS0_5IItemE+544): Routine medialibrary::parser::MetadataAnalyzer::run(medialibrary::parser::IItem&) at /mnt/ssd/vlc-android/medialibrary/medialibrary/build-android-armeabi-v7a/../src/metadata_services/MetadataParser.cpp:126
Stack frame #02 pc 000e9649 /data/app/org.videolan.vlc.debug-2/lib/arm/libmla.so (_ZN12medialibrary6parser6Worker8mainloopEv+2208): Routine medialibrary::parser::Worker::mainloop() at /mnt/ssd/vlc-android/medialibrary/medialibrary/build-android-armeabi-v7a/../src/parser/ParserWorker.cpp:214
Stack frame #03 pc 000ea693 /data/app/org.videolan.vlc.debug-2/lib/arm/libmla.so (_ZNSt6__ndk114__thread_proxyINS_5tupleIJNS_10unique_ptrINS_15__thread_structENS_14default_deleteIS3_EEEEMN12medialibrary6parser6WorkerEFvvEPS9_EEEEEPvSE_+42): Routine _ZNSt6__ndk18__invokeIMN12medialibrary6parser6WorkerEFvvEPS3_JEvEEDTcldsdeclsr3std6__ndk1E7forwardIT0_Efp0_Efp_spclsr3std6__ndk1E7forwardIT1_Efp1_EEEOT_OS7_DpOS8_ at /mnt/ssd/vlc-android/toolchains/arm/bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../include/c++/4.9.x/type_traits:4286
Stack frame #04 pc 0003f893 /system/lib/libc.so (_ZL15__pthread_startPv+30)
Stack frame #05 pc 00019f75 /system/lib/libc.so (__start_thread+6)
item.parentFolderFs()->device()->isRemovable()
device() shouldn't be accessed unconditionally, and a DeviceRemovedException should be thrown