DropletCreateActivity crash

Actual behaviour:
- There is one/more blank droplet option which causes the activity to terminate due to resource not found.

Screenshot:
-

Logcat:
- 07-21 00:40:28.000 12721-12721/in.tosc.digitaloceanapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: in.tosc.digitaloceanapp, PID: 12721
android.content.res.Resources$NotFoundException: Resource ID #0x0
at android.content.res.ResourcesImpl.getValueForDensity(ResourcesImpl.java:224)
at android.content.res.Resources.getDrawableForDensity(Resources.java:876)
at android.content.res.Resources.getDrawable(Resources.java:819)
at android.content.Context.getDrawable(Context.java:605)
at android.support.v4.content.ContextCompat.getDrawable(ContextCompat.java:358)
at in.tosc.digitaloceanapp.adapters.ImageAdapter.selectImage(ImageAdapter.java:113)
at in.tosc.digitaloceanapp.adapters.ImageAdapter$1.onClick(ImageAdapter.java:75)
at android.view.View.performClick(View.java:6314)
at android.view.View$PerformClick.run(View.java:24790)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6582)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:460)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)