wsd: more informative callback failure error message

Change-Id: I8d84af03be2bd051ec03d12528dd98b245b982d0
Reviewed-on: https://gerrit.libreoffice.org/67998
Reviewed-by: Szymon Kłos <szymon.klos@collabora.com>
Tested-by: Szymon Kłos <szymon.klos@collabora.com>
(cherry picked from commit f6a35eab4f7bcbbbb26d4fc1084d78bc3a19ad76)
Reviewed-on: https://gerrit.libreoffice.org/67506

kit/ChildSession.cpp

@@ -2144,7 +2144,7 @@ void ChildSession::loKitCallback(const int type, const std::string& payload)
     // we want a compilation-time failure in the debug builds; but ERR in the
     // log in the release ones
     default:
-        LOG_ERR("Unknown callback event (" << type << "): " << payload);
+        LOG_ERR("Unknown callback event (" << LOKitHelper::kitCallbackTypeToString(type) << "): " << payload);
 #endif
     }
 }

kit/KitHelper.hpp

@@ -133,6 +133,7 @@ namespace LOKitHelper
             return "SIGNATURE_STATUS";
        }
 
+        assert(!"Missing LOK_CALLBACK type");
         return std::to_string(type);
     }