.gitreview added to dictionaries git submodule

[Michael Weghorn]

https://gerrit.libreoffice.org/c/dictionaries/+/138340
("Add .gitreview used by git-review tool")
added a .gitreview to the dictionaries git repo.

As Eike pointed out in the Gerrit change, this means that people who 
already have a local .gitreview in the submodule need to (re)move that 
before updating the submodule:

> Note this when checking out on an existing tree with  ./g pull -r  where .gitreview exists already results in
> 
>   error: The following untracked working tree files would be overwritten by checkout:
>           .gitreview
>   Please move or remove them before you switch branches.
>   Aborting
>   fatal: Unable to checkout 'bcf7f049315dee2001cc2f7c7eabfbcb0b8ef21a' in submodule path 'dictionaries'
> 
> Please announce on the dev list, the usual generated by gitreview content is identical, but in case someone did modifications the file should be moved out of the way, otherwise must be deleted.

Sorry for any inconvenience this may have caused.