From rt#35762:
The customer uses the RSAKeySizes and PGPKeyType config options in kleopatrarc to limit the available algorithms during PGP key creation. This regressed when updating, since those options are no longer considered.

RSAKeySizes lists the allowed key sizes. If the option is present, any size not listed is not avaiable. When a value is negative, its absolute value is used as the default value.
PGPKeyType was used to specify whether a key is DSA, Elgamal, or RSA. Any value that is not "DSA+ELG" or "DSA" (notably, this includes the option being set to an empty string) is interpreted as RSA. Since we no longer allow creating dsa/elgamal keys, this means we should select RSA whenever this option is set to anything. (we have other options for setting the default algorithm now, this is just for backwards compatibility)

We also must use the immutability of PGPKeyType to disable the algorithm combo