Fix json api bind IP

Only the port was being used, the IP was being ignored and it was always
binding to localhost.

llarp/rpc/rpc.cpp

@@ -423,18 +423,18 @@ namespace llarp
       bool
       Start(const std::string& addr)
       {
-        uint16_t port = 0;
-        auto idx      = addr.find_first_of(':');
-        Addr netaddr;
-        if(idx != std::string::npos)
-        {
-          port    = std::stoi(addr.substr(1 + idx));
-          netaddr = Addr(addr.substr(0, idx));
-        }
         sockaddr_in saddr;
         saddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
         saddr.sin_family      = AF_INET;
-        saddr.sin_port        = htons(port);
+        saddr.sin_port        = 0;
+
+        auto idx = addr.find_first_of(':');
+        if(idx != std::string::npos)
+        {
+          Addr netaddr{addr.substr(0, idx), addr.substr(1 + idx)};
+          saddr.sin_addr.s_addr = netaddr.ton();
+          saddr.sin_port        = htons(netaddr.port());
+        }
         return _handler.ServeAsync(router->netloop(), router->logic(),
                                    (const sockaddr*)&saddr);
       }