show error message

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.java

@@ -1812,6 +1812,9 @@ public class FileDisplayActivity extends HookActivity
                 FileDetailFragment fileDetailFragment = (FileDetailFragment) getSecondFragment();
                 fileDetailFragment.getFileDetailActivitiesFragment().reload();
             }
+        } else {
+            Snackbar.make(getSecondFragment().getView(), R.string.file_version_restored_error,
+                    Snackbar.LENGTH_LONG).show();
         }
 
     }

src/main/res/values/strings.xml

@@ -800,4 +800,5 @@
     <string name="restore">Restore file</string>
     <string name="new_version_was_created">New version was created</string>
     <string name="file_version_restored_successfully">Successfully restored file version.</string>
+    <string name="file_version_restored_error">Error restoring file version!</string>
 </resources>