Revert "Added a more specific error message on export"

This reverts commit 00c689d625d0243577c225612aa86aa6a85274c4.

Reason: "Missing template" is just one possible explanation for
`err` being != OK here, it does not make sense to hardcode it in
the generic error message (and break translations doing so).

editor/editor_node.cpp

@@ -491,7 +491,7 @@ void EditorNode::_fs_changed() {
 					err = platform->export_project(preset, export_defer.debug, export_defer.path);
 				}
 				if (err != OK) {
-					ERR_PRINTS(vformat(TTR("Project export failed with error code %d. Missing template?"), (int)err));
+					ERR_PRINTS(vformat(TTR("Project export failed with error code %d."), (int)err));
 				}
 			}
 		}