Stop logging when path is excluded

This causes logging a lot and reporting to sentry which can
cause performance issues.

changelogs/unreleased/security-remove-validate-path-logging-8-64.yml

+---
+title: Stop logging when path is excluded
+merge_request:
+author:
+type: security

internal/staticpages/servefile.go

@@ -37,7 +37,6 @@ func (s *Static) ServeExisting(prefix urlprefix.Prefix, cache CacheMode, notFoun
 		// %20 in their name.
 		relativePath, err := s.validatePath(prefix.Strip(r.URL.Path))
 		if err != nil {
-			log.WithRequest(r).WithError(err).Error()
 			notFoundHandler.ServeHTTP(w, r)
 			return
 		}