Bump minimum overlay version to 35 (#4622)

Closes #4620

This changes bumps the minimum overlay version to match the version in
`v22.0.0`. Now that the network has upgraded to protocol 22, there's no
reason to keep older clients connected.

src/main/Config.cpp

@@ -147,7 +147,7 @@ Config::Config() : NODE_SEED(SecretKey::random())
     LEDGER_PROTOCOL_VERSION = CURRENT_LEDGER_PROTOCOL_VERSION;
     LEDGER_PROTOCOL_MIN_VERSION_INTERNAL_ERROR_REPORT = 18;
 
-    OVERLAY_PROTOCOL_MIN_VERSION = 33;
+    OVERLAY_PROTOCOL_MIN_VERSION = 35;
     OVERLAY_PROTOCOL_VERSION = 36;
 
     VERSION_STR = STELLAR_CORE_VERSION;