How to change nginx source code when using easyengine?

Hi,

I need to increase the NGX_MAX_ERROR_STR in nginx source code src/core/ngx_log.h. This variable is the only way I've found to increase the error string max size before truncation (2048).
Since easyengine manages the stack installation and updates, how can I change this? Where is the nginx source code?
Please help.

Thanks