Bash brace expansion to remove part of filename

To use a brace command to remove a suffix, such as .minimal from the file offlineimap.conf.minimal, use:

mv offlineimap.conf{.minimal,}

More on brace expansion

The idea here is that brace expansion creates a series of strings using the comma-separated list of strings between the braces:

$ echo a{b,c}
ab ac

In your first use, the first of the two strings is empty:

$ echo a{,c}
a ac

In the desired solution, we switch it so that the second of the two strings is empty:

$ echo a{b,}
ab a

Or:

$ echo offlineimap.conf{.minimal,}
offlineimap.conf.minimal offlineimap.conf