add option to unmask Ep3 whispers on proxy server, and prevent this from working on newserv

src/Client.hh

@@ -79,6 +79,7 @@ public:
     PROXY_RED_NAME_ENABLED              = 0x0000200000000000,
     PROXY_BLANK_NAME_ENABLED            = 0x0000400000000000,
     PROXY_BLOCK_FUNCTION_CALLS          = 0x0000800000000000,
+    PROXY_EP3_UNMASK_WHISPERS           = 0x0008000000000000,
     // clang-format on
   };