SSL 3.0 and TLS ciphersuite values are two bytes long

Change-Id: I3ea2846fd4273efe654358ad4a317cb9b3670181
Reviewed-on: https://code.wireshark.org/review/4942
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
Tested-by: Martin Kaiser <wireshark@kaiser.cx>