fix: non-blocking warning in case failed decoding @url@ variable

mentioned in commit af0e49c1

mentioned in merge request to-be-continuous/samples/mkdocs-on-s3!9 (merged)

mentioned in merge request kicker!57 (merged)

mentioned in merge request doc!14 (merged)

mentioned in merge request to-be-continuous/samples/mkdocs-on-s3!13 (merged)

mentioned in merge request kicker!92 (merged)

mentioned in merge request doc!19 (merged)

mentioned in merge request to-be-continuous/samples/angular-on-s3!81 (merged)

mentioned in merge request cedric3.olivier/mkdocs-on-s3!2 (closed)