Code review comment for lp:~fboucault/camera-app/ui_rewrite

I’m seeing a crash at startup, not 100% reproducible but I can trigger it approximately once every 3 launches (on N7 with image #101):

#0 0xaff57bc8 in AdvancedCameraSettings::hasFlash() const ()
   from /opt/click.ubuntu.com/com.ubuntu.camera/3.0.0.318/lib/arm-linux-gnueabihf/CameraApp/libcamera-qml.so
#1 0xaff587ac in AdvancedCameraSettings::qt_metacall(QMetaObject::Call, int, void**) ()
   from /opt/click.ubuntu.com/com.ubuntu.camera/3.0.0.318/lib/arm-linux-gnueabihf/CameraApp/libcamera-qml.so
#2 0xb6553a3e in Direct (property=..., n=0x0, output=0xbeabcc70,
    object=0x666ac8) at jsruntime/qv4qobjectwrapper.cpp:139
#3 LoadProperty<ReadAccessor::Direct> (notifier=0x0, property=...,
    object=0x666ac8, engine=0x5a9c58) at jsruntime/qv4qobjectwrapper.cpp:179
#4 QV4::QObjectWrapper::getProperty (object=0x666ac8,
    ctx=ctx@entry=0xbeabce38, property=<optimized out>,
    captureRequired=captureRequired@entry=true)
    at jsruntime/qv4qobjectwrapper.cpp:395
#5 0xb6553d34 in QV4::QObjectWrapper::getQmlProperty (this=0xaeba1660,
    ctx=0xbeabce38, qmlContext=<optimized out>, n=<optimized out>,
    revisionMode=QV4::QObjectWrapper::IgnoreRevision, hasProperty=0x0,
    includeImports=true) at jsruntime/qv4qobjectwrapper.cpp:333
#6 0xb6553e6e in QV4::QObjectWrapper::get (m=0xaeba1660, name=...,
    hasProperty=<optimized out>) at jsruntime/qv4qobjectwrapper.cpp:672
#7 0xb655b470 in get (hasProperty=<optimized out>, name=...,
    this=<optimized out>) at jsruntime/qv4object_p.h:244
#8 QV4::Runtime::getProperty (ctx=0xbeabce38, object=..., name=...)
    at jsruntime/qv4runtime.cpp:672
#9 0xaff1799e in ?? ()