OpenFlow: Capatilize O and F of OpenFlow (when use Decode as)

Remove also a trailing whitespace in OpenFlow TCP port preference

Change-Id: I5c3f42e634e0fee4fecf1a7f2dd1c75a68165b45
Reviewed-on: https://code.wireshark.org/review/6113
Reviewed-by: Michael Mann <mmann78@netscape.net>