Handle IO errors for contact import

[JoGir]

see handleActivityResult ContactsFragment:240

java.lang.RuntimeException: Failure delivering result ResultInfo{who=android:fragment:0, request=1000, result=-1, data=Intent { dat=content://com.android.providers.downloads.documents/document/772 flg=0x43 }} to activity {de.qabel.qabel/de.qabel.qabelbox.activities.MainActivity}: java.io.FileNotFoundException: No such file or directory
    at android.app.ActivityThread.deliverResults(ActivityThread.java:3553)
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:3596)
    at android.app.ActivityThread.access$1300(ActivityThread.java:151)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1369)
    at android.os.Handler.dispatchMessage(Handler.java:110)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:5292)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.io.FileNotFoundException: No such file or directory
    at android.database.DatabaseUtils.readExceptionWithFileNotFoundExceptionFromParcel(DatabaseUtils.java:146)
    at android.content.ContentProviderProxy.openTypedAssetFile(ContentProviderNative.java:682)
    at android.content.ContentResolver.openTypedAssetFileDescriptor(ContentResolver.java:1089)
    at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:929)
    at android.content.ContentResolver.openFileDescriptor(ContentResolver.java:786)
    at android.content.ContentResolver.openFileDescriptor(ContentResolver.java:741)
    at de.qabel.qabelbox.contacts.view.views.ContactsFragment.onActivityResult(ContactsFragment.kt:237)