crash fix

ngx_http_uploadprogress_module.c

       return NGX_ERROR;
     }
 
+    ctx->read_event_handler = r->read_event_handler;
     ngx_http_set_ctx(r, ctx, ngx_http_uploadprogress_module);
     r->read_event_handler = ngx_http_uploadprogress_event_handler;
     return rc;