Fix: Address PR review feedback for openDCIM module

Add ARTIFACTS_ON_DISK side effect and fetch payload note in docs.

documentation/modules/exploit/linux/http/opendcim_install_sqli_rce.md

@@ -104,6 +104,10 @@ deployments are configured in the wild. No HTTP credentials are needed.
 `HttpPassword` accordingly. Any valid Apache credential is enough - `install.php` has no
 role check.
 
+**Note:** The fetch payload handler is not supported with Target 0 (Unix/Linux Command Shell)
+since standard fetch tools (curl, wget, etc.) are typically not available in the target's
+execution context (`exec()` via Graphviz dot path).
+
 ## Verification Steps
 
 1. Start msfconsole