Increase client body read timeout

This is suspected to have dropped the gRPC stream for the
execution results causing reconnects almost every minute

Author: Taucher2003

container/config-generator/templates/nginx.default.conf.erb

@@ -109,6 +109,7 @@ server {
     grpc_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 
     # Disable buffering for streaming
+    client_body_timeout 1h;
     grpc_read_timeout 1h;
     grpc_send_timeout 1h;