Add test case for ITS#4100

Could not duplicate problem using correct form:
	delete: userCertificate;binary
Improper form
	delete: userCertificate
produces error as expected.

tests/scripts/test021-certificate

@@ -153,6 +153,7 @@ userCertificate;binary::
  5MCKLu9bGJUjsKnGdm/KpaNwaNo=
 
 dn: cn=Jennifer Smith,ou=Alumni Association,ou=People,dc=example,dc=com
+changetype: modify
 add: userCertificate;binary
 userCertificate;binary::
  MIIDjDCCAvWgAwIBAgIBAzANBgkqhkiG9w0BAQQFADB3MQswCQYDVQQGEwJVUzET
@@ -197,6 +198,32 @@ userCertificate;binary::
  T8k50x4C7oE8HwZuEEB4FM7S1Zig3dfeJ8MJgdaLqt5/U9Ip/hZdzG2dsUsIceH/
  5MCKLu9bGJUjsKnGdm/KpaNwaNo=
 
+dn: cn=Mark Elliot,ou=Alumni Association,ou=People,dc=example,dc=com
+changetype: modify
+replace: userCertificate;binary
+userCertificate;binary::
+ MIIDjDCCAvWgAwIBAgIBAzANBgkqhkiG9w0BAQQFADB3MQswCQYDVQQGEwJVUzET
+ MBEGA1UECBMKQ2FsaWZvcm5pYTEfMB0GA1UEChMWT3BlbkxEQVAgRXhhbXBsZSwg
+ THRkLjETMBEGA1UEAxMKRXhhbXBsZSBDQTEdMBsGCSqGSIb3DQEJARYOY2FAZXhh
+ bXBsZS5jb20wHhcNMDMxMDE3MTYzNTM1WhcNMDQxMDE2MTYzNTM1WjCBnjELMAkG
+ A1UEBhMCVVMxETAPBgNVBAgTCE1pY2hpZ2FuMR8wHQYDVQQKExZPcGVuTERBUCBF
+ eGFtcGxlLCBMdGQuMRswGQYDVQQLExJBbHVtbmkgQXNzb2ljYXRpb24xEjAQBgNV
+ BAMTCUplbiBTbWl0aDEqMCgGCSqGSIb3DQEJARYbamVuQG1haWwuYWx1bW5pLmV4
+ YW1wbGUuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDpnXWAL0VkROGO
+ 1Rg8J3u6F4F7yMqQCbUMsV9rxQisYj45+pmqiHV5urogvT4MGD6eLNFZKBn+0KRn
+ i++uu7gbartzpmBaHOlzRII9ZdVMFfrT2xYNgAlkne6pb6IZIN9UONuH/httENCD
+ J5WEpjZ48D1Lrml/HYO/W+SAMkpEqQIDAQABo4H/MIH8MAkGA1UdEwQCMAAwLAYJ
+ YIZIAYb4QgENBB8WHU9wZW5TU0wgR2VuZXJhdGVkIENlcnRpZmljYXRlMB0GA1Ud
+ DgQWBBTB2saht/od/nis76b9m+pjxfhSPjCBoQYDVR0jBIGZMIGWgBRLbyEaNiTS
+ kPlDsFNHLX3hwOaYI6F7pHkwdzELMAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlm
+ b3JuaWExHzAdBgNVBAoTFk9wZW5MREFQIEV4YW1wbGUsIEx0ZC4xEzARBgNVBAMT
+ CkV4YW1wbGUgQ0ExHTAbBgkqhkiG9w0BCQEWDmNhQGV4YW1wbGUuY29tggEAMA0G
+ CSqGSIb3DQEBBAUAA4GBAIoGPc/AS0cNkMRDNoMIzcFdF9lONMduKBiSuFvv+x8n
+ Cek+LUdXxF59V2NPKh2V5gFh5xbAchyv6FVBnpVtPdB5akCr5tdFQhuBLUXXDk/t
+ THGpIWt7OAjEmpuMzsz3GUB8Zf9rioHOs1DMw+GpzWdnFITxXhAqEDc3quqPrpxZ
+-
+delete: userCertificate;binary
+
 EOMODS
 
 RC=$?