bump metasploit credential to 6.0.5

[zgoldman-r7]

This bumps the metasploit-credential gem to version 6.0.5 in order to fix a bug with credential imports.

Verification

-Import a credential of type NTLMHash, PostgresMD5, or KrbEncKey, where the key has uppercase values
-Delete that credential core
-Import the credential again
Previously, this will give an error on import. This should now yield successful imports on the version bump

[jmartin-tech]

Before:

msf6 > creds add user:postgres postgres:md5BE86a79bf2043622d58d5453c47d4860
msf6 > creds
Credentials
===========

host  origin  service  public    private                              realm  private_type  JtR Format
----  ------  -------  ------    -------                              -----  ------------  ----------
                       postgres  md5be86a79bf2043622d58d5453c47d4860         Postgres md5  raw-md5,postgres

msf6 > creds -d
Credentials
===========

host  origin  service  public    private                              realm  private_type  JtR Format
----  ------  -------  ------    -------                              -----  ------------  ----------
                       postgres  md5be86a79bf2043622d58d5453c47d4860         Postgres md5  raw-md5,postgres

[*] Deleted 1 creds
msf6 > creds add user:postgres postgres:md5BE86a79bf2043622d58d5453c47d4860
[-] Failed to add : Validation failed: Data has already been taken

After:

msf6 > creds add user:postgres postgres:md5BE86a79bf2043622d58d5453c47d4860
msf6 > creds
Credentials
===========

host  origin  service  public    private                              realm  private_type  JtR Format
----  ------  -------  ------    -------                              -----  ------------  ----------
                       postgres  md5be86a79bf2043622d58d5453c47d4860         Postgres md5  raw-md5,postgres

msf6 > creds -d
Credentials
===========

host  origin  service  public    private                              realm  private_type  JtR Format
----  ------  -------  ------    -------                              -----  ------------  ----------
                       postgres  md5be86a79bf2043622d58d5453c47d4860         Postgres md5  raw-md5,postgres

[*] Deleted 1 creds
msf6 > creds add user:postgres postgres:md5BE86a79bf2043622d58d5453c47d4860
msf6 > creds
Credentials
===========

host  origin  service  public    private                              realm  private_type  JtR Format
----  ------  -------  ------    -------                              -----  ------------  ----------
                       postgres  md5be86a79bf2043622d58d5453c47d4860         Postgres md5  raw-md5,postgres

[cgranleese-r7]

Release Notes

This PR fixes an issue with credentials being normalized to lowercase inconsistently, causing collisions with uppercase data. Relevant credentials are now automatically normalized to lowercase on insert and lookup.