fboss2 bgp config: address clang-tidy findings

Drop the unused parseInt using-declaration in the peer-group
dispatcher (misc-unused-using-decls).

Author: hillol-nexthop

fboss/cli/fboss2/commands/config/protocol/bgp/peer-group/CmdConfigProtocolBgpPeerGroup.cpp

@@ -90,7 +90,6 @@ using PeerGroup = bgp::thrift::PeerGroup;
 using bgpcli::err;
 using bgpcli::ok;
 using bgpcli::parseBool;
-using bgpcli::parseInt;
 using bgpcli::parseNonNegInt32;
 using bgpcli::parseNonNegInt64;
 using bgpcli::Result;