remove epic version for b2handle

Hi Jie,

there is no single 'b2handle version'; rather I think it is likely a version for each of the server-side components:

1. the Handle server version; this you can probably get somewhere from the Handle installation path
2. the reverse-lookup servlet version; this is deployed in the apps directory of each HS; may be a bit tricky to find out. It may simply be left out then as as it does not change too often and it is just a small component.

So handle sevrer version is best match, probably.

Note that we should not call this the "epic" version as there is no epic server side component since a long time now. It was discontinued for EUDAT years ago.

Best, Tobias