Touching the Panic app list crashes if no market is installed.

If the list of connected panic apps is <= 1 and you press on it Briar will crash if no market is installed:
org.briarproject.briar E/ACRA: ACRA caught a ActivityNotFoundException for org.briarproject.briar android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.VIEW dat=market://details?id=info.guardianproject.ripple }