[plugins/file] do not stop when an entry is found

The plugin currently stops when when an entry is found. This does not
let the following plugins to run, and it makes no sense.

Signed-off-by: Andrea Barberio <insomniac@slackware.it>

plugins/file/plugin.go

@@ -165,8 +165,7 @@ func Handler6(req, resp dhcpv6.DHCPv6) (dhcpv6.DHCPv6, bool) {
 			}
 		}
 	}
-	// XXX: We should maybe allow other plugins to run after this to add other options/handle non-IANA requests
-	return resp, true
+	return resp, false
 }
 
 // Handler4 handles DHCPv4 packets for the file plugin