nocommit does not make sense in unannex mode

Commands.hs

@@ -122,6 +122,10 @@ addCmd file = inBackend file err $ do
 {- Undo addCmd. -}
 unannexCmd :: FilePath -> Annex ()
 unannexCmd file = notinBackend file err $ \(key, backend) -> do
+	nocommit <- Annex.flagIsSet NoCommit
+        if (nocommit)
+		then error "--nocommit cannot be used in unannex mode"
+		else do
 			Backend.removeKey backend key
 			logStatus key ValueMissing
 			g <- Annex.gitRepo