Bugfix of NullPointerException in DataProvider. Could not reproduce bug, stack trace below.

java.lang.NullPointerException
	at de.skubware.opentraining.db.DataProvider.saveSyncedExercises(DataProvider.java:190)
	at de.skubware.opentraining.activity.settings.sync.SyncFinishedDialog.saveExercises(SyncFinishedDialog.java:228)
	at de.skubware.opentraining.activity.settings.sync.SyncFinishedDialog.access$000(SyncFinishedDialog.java:57)
	at de.skubware.opentraining.activity.settings.sync.SyncFinishedDialog$1.onClick(SyncFinishedDialog.java:91)
	at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loop(Looper.java:136)
	at android.app.ActivityThread.main(ActivityThread.java:5001)
	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:785)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
	at dalvik.system.NativeStart.main(Native Method)
Bugfixe: NullPointerException in DataProvider. Could not reproduce, stack trace below.

java.lang.NullPointerException
	at de.skubware.opentraining.db.DataProvider.saveSyncedExercises(DataProvider.java:190)
	at de.skubware.opentraining.activity.settings.sync.SyncFinishedDialog.saveExercises(SyncFinishedDialog.java:228)
	at de.skubware.opentraining.activity.settings.sync.SyncFinishedDialog.access$000(SyncFinishedDialog.java:57)
	at de.skubware.opentraining.activity.settings.sync.SyncFinishedDialog$1.onClick(SyncFinishedDialog.java:91)
	at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loop(Looper.java:136)
	at android.app.ActivityThread.main(ActivityThread.java:5001)
	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:785)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
	at dalvik.system.NativeStart.main(Native Method)