If there's a lockfile, but it's out of sync with the Gemfile because a
dependency has been deleted, and frozen mode is set, Bundler will print
the following strange error:
```
$ bundle add rake
, but the lockfile can't be updated because frozen mode is set
You have deleted from the Gemfile:
* rake (~> 13.2)
Run `bundle install` elsewhere and add the updated Gemfile to version control.
```
This commit changes the error to:
```
Some dependencies were deleted from your gemfile, but the lockfile can't be updated because frozen mode is set
You have deleted from the Gemfile:
* rake (~> 13.2)
Run `bundle install` elsewhere and add the updated Gemfile to version control.
```
https://github.com/rubygems/rubygems/commit/452da4048d