Update eosio.system-regproxy-rc.md

removed deprecated arbitration clauses

contracts/eosio.system/eosio.system-regproxy-rc.md

 # Action - `{{ regproxy }}`
 
-This Contract is legally binding and can be used in the event of a dispute. 
-
 ### Description
 
 The `{{ regproxy }}` action... 
@@ -15,5 +13,3 @@ The `{{ regproxy }}` action requires the following `inputs` and `input types`:
 | `{{ regproxy }}` | `{{ proxyVar }}`<br/>`{{ isproxyVar }}` | `{{ account_name }}`<br/>`{{ bool }}` |
 
 As an authorized party I {{ signer }} wish to UNKNOWN
-
-All disputes arising from this contract shall be resolved in the EOS Core Arbitration Forum.