Fix possible crash when no bankroll is set

app/src/main/java/net/pokeranalytics/android/ui/fragment/SessionFragment.kt

@@ -122,7 +122,12 @@ class SessionFragment : PokerAnalyticsFragment(), RowRepresentableDelegate {
 
 	override fun onRowValueChanged(value: Any?, row: RowRepresentable) {
 		sessionHasBeenCustomized = true
-		currentSession.updateValue(value, row)
+		try {
+			currentSession.updateValue(value, row)
+		} catch (e: IllegalStateException) {
+			Toast.makeText(context, e.message, Toast.LENGTH_LONG).show()
+			return
+		}
 		sessionAdapter.refreshRow(row)
 		when (row) {
 			SessionRow.CASHED_OUT, SessionRow.PRIZE, SessionRow.NET_RESULT, SessionRow.BUY_IN, SessionRow.TIPS,