* Stricter handling of multi-namespace handling

* This occurs in cases where there are more than one XML namespaces in a config tree, such as `augment`:ed trees.
  * Affects all parts of the system, including datastore, backend, restconf and cli.
* Invalid api-path syntax (eg non-matching yang) error changed from 412 operation-failed to 400 Bad request invalid-value, or unknown-element.

apps/restconf/restconf_lib.c

@@ -526,6 +526,7 @@ api_return_err(clicon_handle h,
 	    FCGX_FPrintF(r->out, "%s", cbuf_get(cb));
 	    FCGX_FPrintF(r->out, "}\r\n");
 	}
+	break;
     default:
 	clicon_err(OE_YANG, EINVAL, "Invalid media type %d", media);
 	goto done;