chore: fix wrong typo in message

Author: canbingzt

Diff for: core/src/main/java/org/springframework/ldap/support/LdapUtils.java

@@ -450,7 +450,7 @@ public static LdapName removeFirst(Name dn, Name pathToRemove) {
 	 */
 	public static LdapName prepend(Name dn, Name pathToPrepend) {
 		Assert.notNull(dn, "dn must not be null");
-		Assert.notNull(pathToPrepend, "pathToRemove must not be null");
+		Assert.notNull(pathToPrepend, "pathToPrepend must not be null");
 
 		LdapName result = newLdapName(dn);
 		try {