finagle-mux: wireshark dissector fixups
finagle-mux: wireshark dissector fixups

Problem

The wireshark mux dissector omits the deprecated but in-use rerr type
code and is off by one on the minimum valid tag. Consequently the heuristic
dissector misses mux handshakes.

Solution

Add the missing message type and fix the minimum tag value.

Result

The mux dissector's heuristic indentifies mux handshakes.

RB_ID=865583

koshelev/finagle,koshelev/finagle,adriancole/finagle,twitter/finagle,adriancole/finagle,koshelev/finagle,twitter/finagle,adriancole/finagle,luciferous/finagle,BuoyantIO/finagle,koshelev/finagle,luciferous/finagle,luciferous/finagle,spockz/finagle,BuoyantIO/finagle,spockz/finagle,BuoyantIO/finagle,luciferous/finagle,spockz/finagle,koshelev/finagle,adriancole/finagle,adriancole/finagle,BuoyantIO/finagle,twitter/finagle,mkhq/finagle,mkhq/finagle,mkhq/finagle,luciferous/finagle,mkhq/finagle,mkhq/finagle,adriancole/finagle,twitter/finagle,mkhq/finagle,BuoyantIO/finagle,twitter/finagle,luciferous/finagle,BuoyantIO/finagle,spockz/finagle,spockz/finagle,koshelev/finagle,spockz/finagle