identical base64 values flagged as different when diffing

[Paul Collins]

I noticed the following output from juju-deployer --diff:

services:
  modified:
    turku-api-fe:
      cfg-config:
        vhost_http_template: !!binary |
          UEZacGNuUjFZV3hJYjNOMElGOWtaV1poZFd4MFh6bzRNRDRLSUNBZ0lGTmxjblpsY2s1aGJXVWdl
          M3NnYzJWeWRtVnlibUZ0WlNCOWZRb0tJQ0FnSUVWeWNtOXlURzluSUNSN1FWQkJRMGhGWDB4UFIx
          OUVTVko5TDN0N0lITmxjblpsY201aGJXVWdmWDB0YUhSMGNDMWxjbkp2Y2k1c2IyY0tJQ0FnSUVO
          MWMzUnZiVXh2WnlBa2UwRlFRVU5JUlY5TVQwZGZSRWxTZlM5N2V5QnpaWEoyWlhKdVlXMWxJSDE5
          TFdoMGRIQXRZV05qWlhOekxteHZaeUJqYjIxaWFXNWxaQW9LSUNBZ0lFRnNhV0Z6SUM5emRHRjBh
          V012WVdSdGFXNHZJQzkxYzNJdmJHbGlMM0I1ZEdodmJqSXVOeTlrYVhOMExYQmhZMnRoWjJWekwy
          UnFZVzVuYnk5amIyNTBjbWxpTDJGa2JXbHVMM04wWVhScFl5OWhaRzFwYmk4S0NpQWdJQ0JRY205
          NGVWSmxjWFZsYzNSeklHOW1aZ29nSUNBZ1VISnZlSGxRY21WelpYSjJaVWh2YzNRZ2IyNEtDaUFn
          SUNCU1pYZHlhWFJsUlc1bmFXNWxJRTl1Q2lBZ0lDQlNaWGR5YVhSbFEyOXVaQ0FsZTFKRlVWVkZV
          MVJmVlZKSmZTQWhMM04wWVhScFl3b2dJQ0FnVW1WM2NtbDBaVkoxYkdVZ1hpOG9MaW9wSkNCaVlX
          eGhibU5sY2pvdkwzUjFjbXQxTFdGd2FTMWhjSEF2SkRFZ1cxQmRDZ29nSUNBZ1BFUnBjbVZqZEc5
          eWVTQXZkWE55TDJ4cFlpOXdlWFJvYjI0eUxqY3ZaR2x6ZEMxd1lXTnJZV2RsY3k5a2FtRnVaMjh2
          WTI5dWRISnBZaTloWkcxcGJpOXpkR0YwYVdNdllXUnRhVzR2UGdvZ0lDQWdJQ0FnSUU5d2RHbHZi
          bk1nU1c1a1pYaGxjeUJHYjJ4c2IzZFRlVzFNYVc1cmN3b2dJQ0FnSUNBZ0lFRnNiRzkzVDNabGNu
          SnBaR1VnVG05dVpRb2dJQ0FnSUNBZ0lGSmxjWFZwY21VZ1lXeHNJR2R5WVc1MFpXUUtJQ0FnSUR3
          dlJHbHlaV04wYjNKNVBnbzhMMVpwY25SMVlXeEliM04wUGdvPQ==
      env-config:
        vhost_http_template: 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

But when the cfg-config value is base64-decoded, it yields the second string. juju-deployer should consider these values identical.