Should update-index --refresh force writing the index in case of racy timestamps?

[Marc Strapetz <marc.strapetz@xxxxxxxxxxx>]

For one of my Git-LFS test repositories, switching between branches 
quite often results in lots of racy index timestamps. Subsequent calls 
to "git update-index --refresh" or "git status" will invoke the "lfs" 
filter over and over again, just to figure out that all entries are 
still up-to-date. Hence, the index will never be rewritten and racy 
timestamps will remain.

To break out of this state, it seems favorable to write the index if any 
racy timestamp is detected. We will be able to provide a patch if this 
change sounds reasonable.

-Marc