Fix mod_auth_openidc parameters

A typo in the data type cause an exception with recent Puppet 8
versions:

```
Error: The key '["IDTokenEncryptedResponseAlg"]' is declared more than once (file: /etc/puppetlabs/code/environments/production/modules/apache/types/oidcsettings.pp, line: 41, column: 57) on node b4d45d8831d5.mtgrj3ika5nejlcpzgeeecg0la.cx.internal.cloudapp.net
```

According to the upstream repository configuration file, this is a
copy-paste error.

types/oidcsettings.pp

@@ -38,7 +38,7 @@
     Optional['ClientJwksUri']                           => Stdlib::HTTPSUrl,
     Optional['IDTokenSignedResponseAlg']                => Enum['RS256', 'RS384', 'RS512', 'PS256', 'PS384', 'PS512', 'HS256', 'HS384', 'HS512', 'ES256', 'ES384', 'ES512'],
     Optional['IDTokenEncryptedResponseAlg']             => Enum['RSA1_5', 'A128KW', 'A256KW', 'RSA-OAEP'],
-    Optional['IDTokenEncryptedResponseAlg']             => Enum['A128CBC-HS256', 'A256CBC-HS512', 'A256GCM'],
+    Optional['IDTokenEncryptedResponseEnc']             => Enum['A128CBC-HS256', 'A256CBC-HS512', 'A256GCM'],
     Optional['UserInfoSignedResposeAlg']                => Enum['RS256', 'RS384', 'RS512', 'PS256', 'PS384', 'PS512', 'HS256', 'HS384', 'HS512', 'ES256', 'ES384', 'ES512'],
     Optional['UserInfoEncryptedResponseAlg']            => Enum['RSA1_5', 'A128KW', 'A256KW', 'RSA-OAEP'],
     Optional['UserInfoEncryptedResponseEnc']            => Enum['A128CBC-HS256', 'A256CBC-HS512', 'A256GCM'],