fix some codeql warnings. (#663)

fix some codeql warnings. (#663)

* fix some codeql warnings.

* use c++11 z length modifier in format strings with size_t format arguments.

* don't attempt to upload coverage if token is null or not set.

with the github action flow the CODACY_PROJECT_TOKEN is set and null
for foreign pull requests that don't have access to the secrets.

* double protect token