Merge pull request #780 from Unrud/npe

Fix NPEs

src/main/java/com/nutomic/syncthingandroid/fragments/DeviceListFragment.java

@@ -38,7 +38,9 @@ public class DeviceListFragment extends ListFragment implements SyncthingService
     @Override
     public void onPause() {
         super.onPause();
-        mTimer.cancel();
+        if (mTimer != null) {
+            mTimer.cancel();
+        }
     }
 
     @Override

src/main/java/com/nutomic/syncthingandroid/fragments/FolderFragment.java

@@ -138,7 +138,7 @@ public class FolderFragment extends Fragment
         @Override
         public void onClick(View v) {
             Intent intent = new Intent(getActivity(), FolderPickerActivity.class);
-            if (mFolder.path.length() > 0) {
+            if (!TextUtils.isEmpty(mFolder.path)) {
                 intent.putExtra(FolderPickerActivity.EXTRA_INITIAL_DIRECTORY, mFolder.path);
             }
             startActivityForResult(intent, DIRECTORY_REQUEST_CODE);

src/main/java/com/nutomic/syncthingandroid/fragments/FolderListFragment.java

@@ -46,7 +46,9 @@ public class FolderListFragment extends ListFragment implements SyncthingService
     @Override
     public void onPause() {
         super.onPause();
-        mTimer.cancel();
+        if (mTimer != null) {
+            mTimer.cancel();
+        }
     }
 
     @Override