Merge branch 'mr/cardao/fix-mypy-error' into 'master'

e3.os.platform: Fix mypy error

Closes #25

See merge request it/e3-core!61

src/e3/os/platform.py

@@ -97,7 +97,11 @@ def fetch_system_data(cls) -> None:
             try:
                 import psutil
 
-                cls.core_number = psutil.cpu_count()
+                tmp_core_number = psutil.cpu_count()
+                if not tmp_core_number:
+                    logger.error("psutil.cpu_count() returned None or 0")
+                else:
+                    cls.core_number = tmp_core_number
             except Exception:
                 logger.exception("psutil error")