Fix typo on ssl ElytronMesages

There is a typo in the string of the error message "unknownCipherSuiteName" where it says "Uknown" instead of "Unknown"

The typo can be found on the line linked here: https://github.com/wildfly-security/wildfly-elytron/blob/1.x/ssl/src/main/java/org/wildfly/security/ssl/ElytronMessages.java#L191